GB-115 (Ranquilon)

updated

GB-115 is a dipeptide-like anxiolytic designed at the Zakusov Institute of Pharmacology in Moscow and called Ranquilon in Russia, sold in the West mainly by research suppliers as a spray for anxiety relief that keeps alertness. Its published work is rodent and monkey studies, a small uncontrolled Russian pilot and registered Russian trials with no posted results, and no published randomized trial exists. No study has tested a spray: every studied form is oral or injected.

Cholecystokinin-4 retroanalogue (dipeptide-like anxiolytic)

  • GB-115 is PubChem CID 11281948, C25H30N4O3, molecular weight 434.5, N-(6-phenylhexanoyl)glycyl-L-tryptophan amide; the D-tryptophan version is a different molecule with the opposite effect in animals.
  • The authors describe anxiolytic effects in mice and rats shifting from 0.006 to 0.100 mg/kg intraperitoneally to 0.1 to 5.0 mg/kg orally, with effects that depended on the animal's emotional phenotype.
  • A Russian-language pilot in 31 patients with generalized anxiety disorder reported a fast anxiolytic effect with stimulating properties; its abstract describes no control group, no scale scores and no adverse event counts.
  • NCT05586789 is a randomized, quadruple-masked, placebo-controlled Phase 3 trial in 220 patients that ended in January 2023, with no results posted as of 10 October 2026.
  • A PubMed query on 10 October 2026 returned 23 records for GB-115, and adding intranasal, spray, sublingual, nasal, buccal, transmucosal or transdermal terms returned none.
  • Absolute oral bioavailability was 4.65% in one report, and DailyMed returned no label and openFDA no match for GB-115.

What is GB-115, and what is its regulatory status?

GB-115 is N-(6-phenylhexanoyl)glycyl-L-tryptophan amide, a dipeptide-like retroanalogue of cholecystokinin-4 designed at the Zakusov Institute of Pharmacology in Moscow and called Ranquilon in Russia. It has no FDA label, and Russian secondary pages describe a Valenta Pharm tablet launched in December 2024 without showing a registration number, so registration in Russia is not established here.

GB-115 is PubChem CID 11281948, C25H30N4O3, 434.5 g/mol, with CAS 678996-63-9 among the synonyms. It is N-(6-phenylhexanoyl)glycyl-L-tryptophan amide, which the papers call a dipeptide, a retroanalogue of cholecystokinin-4 (CCK-4) and a tripeptoid analog of CCK-4. Its Russian drug name is Ranquilon, the intervention name in two ClinicalTrials.gov records.

The D-tryptophan version is a different molecule with the opposite effect. The 2007 design paper says L-tryptophan derivatives were anxiolytic and D-tryptophan derivatives anxiogenic, and a 2023 paper calls D-GB-115 a CCK-4 agonist. One 2011 abstract writes GB-115 as Ph(CH2)5CO-Gly-D-Trp-NH2, which conflicts with the 2007 definition and with PubChem; this page uses the L-tryptophan form and treats that formula as a probable error that is not resolved. A vendor vial labeled GB-115 cannot be tied to the L form by the name alone, and no public record ties any vendor material to the studied compound.

The compound was designed at the V.V. Zakusov Institute of Pharmacology in Moscow by Gudasheva, Kolik, Seredenin and colleagues, and a 2007 paper chose it for further study as a promising anxiolytic.

On 10 October 2026 DailyMed returned no label for GB-115 and an openFDA Drugs@FDA query returned no match. A Russian drug reference page lists Valenta Pharm as the holder of Ranquilon, 1 mg tablets for anxiety states in neurasthenia and adjustment disorder on prescription, and a trade news item dated 13 December 2024 reports that Valenta Pharm launched it. Both are secondary pages, and neither shows a registration number or registration date, so this page makes no claim that the drug is registered in Russia until the state register is read.

PubChem: GB-115 identity, the L-tryptophan form, and the D-tryptophan flag

Chemical identity record

PubChem, National Library of Medicine. Compound summary for CID 11281948, N-[2-[[(2S)-1-amino-3-(1H-indol-3-yl)-1-oxopropan-2-yl]amino]-2-oxoethyl]-6-phenylhexanamide (GB-115).

GB-115 is PubChem CID 11281948, C25H30N4O3, 434.5 g/mol, CAS 678996-63-9 (listed among the synonyms), IUPAC name N-[2-[[(2S)-1-amino-3-(1H-indol-3-yl)-1-oxopropan-2-yl]amino]-2-oxoethyl]-6-phenylhexanamide, which is N-(6-phenylhexanoyl)glycyl-L-tryptophan amide. Synonyms include GB115, (-)-GB-115 and N-(1-Oxo-6-phenylhexyl)glycyl-L-tryptophanamide. The papers call it a dipeptide, a retroanalogue of cholecystokinin-4 (CCK-4) and a tripeptoid analog of CCK-4. Its Russian drug name is Ranquilon (the intervention name, with GB-115 as an other name, in the two ClinicalTrials.gov records). The D-tryptophan version is a different molecule with the opposite effect: the 2007 design paper says L-tryptophan derivatives were anxiolytic and D-tryptophan derivatives anxiogenic, and a 2023 paper calls D-GB-115 a CCK-4 agonist (PMID 37582869). One 2011 abstract writes GB-115 as Ph(CH2)5CO-Gly-D-Trp-NH2 (PMID 21476266), which conflicts with the 2007 definition and with PubChem.

Participants / model
Chemical identity, not a clinical population
Treatment
Defined molecule, free form (L-tryptophan amide)
Follow-up
Not applicable
Study design
Chemical database record; original reports
Funding
not stated in the source

Identity record only. This page uses the L-tryptophan form and treats the 2011 D-Trp formula as a probable error that is not resolved against the full text. A vendor vial labeled GB-115 cannot be tied to the L form by the name alone, and no public record ties any vendor material to the studied compound.

Read the original source
2007 design paper: Zakusov Institute analogues of CCK-4, GB-115 active in rats at 0.05 to 0.2 mg/kg

Animal study

Gudasheva TA et al. Bioorg Khim. 2007;33(4):413-20. PMID 17886432.

A 2007 design paper from Gudasheva, Kolik, Seredenin and colleagues made a series of dipeptide analogues of CCK-4 of the formula Ph(CH2)nCO-NH(CH2)mCO-Trp-NH2, based on the structure of CCK-4. GB-115, Ph(CH2)5CO-Gly-L-Trp-NH2, active in rats at 0.05 to 0.2 mg/kg after oral and intraperitoneal administration, was chosen for further study as a promising anxiolytic. A 2013 paper reports NMR work that identified a beta-turn, specifically a betaII-turn, as its biologically active conformation (PMID 24397028). Two review abstracts place GB-115 in the 'creation of dipeptide preparations' project of the V.V. Zakusov Institute of Pharmacology, Moscow, alongside noopept, dilept and GK-2, and call it a 'selective anxiolytic' and 'potential selective anxiolytic' (PMID 30295186, PMID 21899085).

Participants / model
Rats; chemical analogues
Treatment
Oral and intraperitoneal administration in rats
Follow-up
not stated in the source
Study design
Original preclinical and chemistry studies; review abstracts
Funding
not stated in the source

The work is from one institute and its collaborators.

Read the original source
Secondary Russian reference page and trade news: Valenta Pharm prescription tablet, no registration number shown

Regulatory record

RLS (rlsnet.ru) drug reference page for Ranquilon (spelled Rankvilon in its address), and a trade news item dated 2024-12-13; DailyMed label search and openFDA Drugs@FDA query for GB-115, run 10 October 2026.

A Russian drug reference page for Ranquilon lists the holder as Valenta Pharm, 1 mg round tablets of N-(6-phenylhexanoyl)glycyl-L-tryptophan amide, prescription use, adults 18 and over, for anxiety states in neurasthenia and adjustment disorder, contraindicated in hypersensitivity and (in the page text) children under 18, pregnancy and breastfeeding. Adverse reactions listed with frequency unknown include irritability, insomnia, somnolence, daytime somnolence, headache, dizziness, attention impairment, tremor, taste disturbance, a reversible decrease in visual acuity, nausea, diarrhea, arthralgia, proteinuria and asthenia; the page carries an agreement date of 2024-12-23. A trade news item dated 2024-12-13 reports Valenta Pharm launched an original anxiety drug named Ranquilon (Russian spelling Rankvilon) from a price of 990 rubles and calls it the first of a new class of cholecystokinin receptor blockers (a company claim). Neither page shows a registration number or registration date. DailyMed returned no label for GB-115, and the openFDA Drugs@FDA query returned no match.

Participants / model
Records reviewed, not a population
Treatment
Oral 1 mg tablets (Russia)
Follow-up
Not applicable
Study design
Secondary drug-reference and trade pages, not the state register; dated label search
Funding
not stated in the source

Both pages are secondary, and neither shows a registration number or date, so no registration claim is made until the Russian state register is read. The reference page lists somnolence and attention impairment among adverse reactions, which bears on the keeps-alertness wording. The official label was not read.

Read the original source

What did the human studies find?

The human data are a small uncontrolled Russian pilot in 31 patients with generalized anxiety disorder, a poster analysis of 25 patients, and two registered Russian trials with no posted results. The pilot reported a fast anxiolytic effect with stimulating properties, but its abstract describes no control group, so no controlled efficacy result has been published.

A Russian-language study in 31 patients with generalized anxiety disorder (22 women, 9 men, aged 22 to 53), given 1 mg tablets for 21 days, determined an effective dose of 6 mg per day and reported a fast-onset anxiolytic effect with stimulating properties, a beneficial effect on sleep disturbances and autonomic symptoms, favorable changes in attention parameters, reaction time and overall performance, and no initial overactivation, anxiety or sleep disturbance of the kind seen with SSRIs and SNRIs. The authors conclude it is safe and well tolerated, and Seredenin SB is an author. The abstract describes no control group, gives no scale scores and gives no adverse event counts.

A 2022 European Congress of Psychiatry poster abstract from the Zakusov Institute analyzed 25 patients with generalized anxiety disorder (8 men, 17 women, median age 34) given 6 mg daily for 21 days. Median Hamilton Anxiety Rating Scale totals fell from 22 to 19, 13, 9 and 5 on days 3, 7, 14 and 21, and median MFI-20 fell from 70 to 59, 52, 37 and 28 (p < 0.001 for both). No patient had stimulation-related side effects, and the authors describe mild psychostimulant properties. It is a post-hoc analysis that follows the pilot, with no comparator arm reported in the abstract.

ClinicalTrials.gov lists NCT05586789, a randomized, quadruple-masked, placebo-controlled multicenter Phase 3 trial of Ranquilon (GB-115) at 6 mg per day for 28 days in 220 patients with anxiety in neurasthenia and adjustment disorders, ages 18 to 70, sponsored by Valenta Pharm JSC in Russia. It started on 2022-10-12 and completed on 2023-01-03, and no results are posted as of 10 October 2026. The primary outcome is the proportion of patients with a 50% or greater reduction in Hamilton Anxiety Rating Scale score on day 29 plus or minus 1. A second record, NCT06843044, is an open-label Phase 4 comparison of Ranquilon with afobazole (fabomotizole), 250 patients estimated, recruiting, with estimated completion on 2027-12-31. The registry shows the trials were run and gives no outcome.

A PubMed query for the GB-115 names that also contained patients, volunteers, clinical, trial, human or humans returned 6 records: a conformation study, two review abstracts on development, the monkey study, an antidepressant mouse study and the Russian pilot. None is a published randomized controlled trial.

Russian pilot in 31 patients and a 2022 poster analysis of 25 patients, no control group described

Human study

Neznamov GG et al. Zh Nevrol Psikhiatr Im S S Korsakova. 2019;119(8):53-60. PMID 31626171.

A Russian-language study in 31 patients with generalized anxiety disorder (22 women, 9 men, aged 22 to 53), given 1 mg tablets for 21 days, determined an effective dose of 6 mg per day and reported a fast-onset anxiolytic effect with 'stimulating properties', a beneficial effect on sleep disturbances and autonomic symptoms, favorable changes in attention parameters, reaction time and overall performance, and no initial overactivation, anxiety or sleep disturbance of the kind seen with SSRIs and SNRIs. The authors conclude it is safe and well tolerated. The abstract describes no control group, gives no scale scores and gives no adverse event counts. A European Congress of Psychiatry 2022 poster abstract from the Zakusov Institute analyzed 25 patients with GAD (8 men, 17 women, median age 34) given 6 mg daily for 21 days: median HARS total fell from 22 to 19, 13, 9 and 5 on days 3, 7, 14 and 21, and median MFI-20 fell from 70 to 59, 52, 37 and 28 (p < 0.001 for both); no patient had stimulation-related side effects, and the authors describe 'mild psychostimulant properties' (Eur Psychiatry 2022;65 Suppl 1:S388, DOI 10.1192/j.eurpsy.2022.981, no PMID).

Participants / model
Adults with generalized anxiety disorder (31 patients in the pilot, 25 in the poster analysis)
Treatment
Oral tablets, 1 mg tablets for 21 days in the pilot and 6 mg daily for 21 days in the poster analysis
Follow-up
21 days
Study design
Original uncontrolled clinical study as described in its abstract; conference poster abstract with a post-hoc analysis
Funding
not stated in the source

Seredenin SB is an author of the pilot. The poster is a post-hoc analysis that follows the pilot, with no comparator arm reported in its abstract. No control group, scale scores or adverse event counts are in the pilot abstract.

Read the original source
Registered Russian Phase 3, 220 patients, placebo-controlled, no posted results; Phase 4 against afobazole

Trial registry record

ClinicalTrials.gov. NCT05586789. Randomized, quadruple-masked, placebo-controlled multicenter Phase 3 trial of Ranquilon (GB-115) tablets. Sponsor Valenta Pharm JSC, Russia. A second record, NCT06843044, is an open-label Phase 4 comparison with afobazole.

NCT05586789 is a randomized, quadruple-masked, placebo-controlled multicenter Phase 3 trial of Ranquilon 1 mg tablets (GB-115) at 6 mg per day for 28 days in 220 patients (actual) with anxiety in neurasthenia and adjustment disorders, sponsor Valenta Pharm JSC, Russia, ages 18 to 70; start 2022-10-12, completion 2023-01-03, last update 2023-07-27, no results posted as of 2026-10-10. The primary outcome is the proportion of patients with a 50% or greater reduction in Hamilton Anxiety Rating Scale score on day 29 plus or minus 1. A second record, NCT06843044, is an open-label Phase 4 comparison of Ranquilon 6 mg per day with afobazole (fabomotizole) 30 mg per day, 250 patients estimated, recruiting, start 2025-01-13, estimated completion 2027-12-31, last update 2025-07-08.

Participants / model
Adults 18 to 70 with anxiety in neurasthenia and adjustment disorders; 220 enrolled in the Phase 3 (actual), 250 estimated in the Phase 4
Treatment
Oral GB-115 (Ranquilon) tablets, 6 mg per day, against placebo for 28 days in the Phase 3 and against afobazole in the Phase 4
Follow-up
28 days in the Phase 3; start 2022-10-12, completion 2023-01-03
Study design
Phase 3 randomized, quadruple-masked, placebo-controlled multicenter trial; Phase 4 open-label comparison
Funding
Sponsor Valenta Pharm JSC, Russia (registry record)

The registry shows the trials were run and gives no outcome. No results are posted for the Phase 3, and the Phase 4 is recruiting. The Phase 3 result would need to be read again before this page is updated.

Read the original source
PubMed, 10 October 2026: 23 records, none on a spray form, none a published randomized trial

PubMed search record

PubMed search run 10 October 2026: "GB-115"[tiab] OR GB115[tiab] OR "GB 115"[tiab] and the chemical names, with follow-up queries adding intranasal, spray, sublingual, nasal, buccal, transmucosal or transdermal, and adding patients, volunteers, clinical, trial, human or humans.

The search returned 23 records, and the titles were read for all of them. Adding intranasal, spray, sublingual, nasal, buccal, transmucosal or transdermal returned 0 records. Every dosage form in the abstracts is oral (tablets, micronized powder, crystalline substance) or intraperitoneal injection, and oral bioavailability was 4.65%. A spray has no pharmacokinetic, efficacy or safety source in the records reviewed. Adding patients, volunteers, clinical, trial, human or humans returned 6 records (a conformation study, two review abstracts on development, the monkey study, the antidepressant mouse study and the Russian pilot); none is a published randomized controlled trial. The Phase 3 is registered with no posted results. Every paper read comes from the Zakusov Institute network or its collaborators, apart from a paramecium paper on D-GB-115 (PMID 37582869).

Participants / model
Records reviewed, not a population
Treatment
Not applicable
Follow-up
Searches run on 10 October 2026
Study design
Dated literature search
Funding
not stated in the source

An absence finding as of 10 October 2026, not proof that no unpublished or unindexed work exists.

Read the original source

What did the rodent and monkey studies find?

In mice and rats GB-115 was anxiolytic at 0.006 to 0.100 mg/kg intraperitoneally and 0.1 to 5.0 mg/kg orally, according to the authors, with effects that depended on the animal's emotional phenotype. In rats it kept its effect over 30 days without withdrawal signs, and in four rhesus monkeys it changed stress-related measures, all in studies from one Russian institute network.

In inbred mice and rats that differ in emotional stress response, GB-115 at 0.006 to 0.100 mg/kg dose-dependently raised open-field activity in BALB/c mice with no effect on C57Bl/6 mice, and at 0.025 and 0.05 mg/kg was anxiolytic in MR rats but not MNRA rats. Orally, anxiolytic effects appeared at 0.1 to 0.5 mg/kg in outbred mice, 0.1 and 5.0 mg/kg in BALB/c mice and 0.5 to 0.7 mg/kg in outbred rats, which the authors describe as a shift from 0.006 to 0.100 mg/kg intraperitoneally to 0.1 to 5.0 mg/kg orally. Effects depend on the animal's emotional phenotype, and some groups showed none.

In rats given 0.1 mg/kg intraperitoneally daily for 30 days, GB-115 kept its anxiolytic effect in the elevated plus-maze, and stopping it did not produce anxiety, aggression or lowered convulsive threshold, while stopping diazepam at 4.0 mg/kg/day did. In rats withdrawn from phenazepam or diazepam, GB-115 at 0.1 and 0.5 mg/kg intraperitoneally was anxiolytic 24 to 48 hours later. In mice, 0.025 mg/kg reduced immobility time in the Porsolt test, an effect smaller than amitriptyline at 10 mg/kg, with no change in spontaneous locomotor activity after acute dosing.

In four male rhesus monkeys, 1 mg tablets for 7 days then 2 mg for 7 days reduced time in the upper part of the cage at 1 mg and the cortisol to DHEA-S ratio at 2 mg, with effects the authors call comparable to phenazepam. The monkeys received GB-115 first and phenazepam second, and no placebo is described.

None of these abstracts measures sedation or vigilance directly, so the keeps-alertness wording has only indirect animal support.

Mice and rats: anxiolytic at 0.006 to 0.100 mg/kg intraperitoneally and 0.1 to 5.0 mg/kg orally; CCK-4 target

Animal study

Kolik LG et al. Bull Exp Biol Med. 2013;155(2):200-3. PMID 24130989.

In inbred mice and rats that differ in emotional stress response, GB-115 at 0.006 to 0.100 mg/kg dose-dependently raised open-field activity in BALB/c mice with no effect on C57Bl/6 mice, and at 0.025 and 0.05 mg/kg was anxiolytic in MR rats but not MNRA rats (PMID 12910281). Orally, anxiolytic effects appeared at 0.1 to 0.5 mg/kg in outbred mice, 0.1 and 5.0 mg/kg in BALB/c mice, and 0.5 to 0.7 mg/kg in outbred rats, which the authors describe as a shift from 0.006 to 0.100 mg/kg intraperitoneally to 0.1 to 5.0 mg/kg orally. Activation of CCK-4 type 2 receptors abolished the antianxiety effect in BALB/c mice, GB-115 prevented CCK-4-induced anxiety in C57Bl/6 mice and outbred rats and did not prevent yohimbine-induced anxiety, so the authors conclude CCK-4 and GB-115 share a pharmacological target (PMID 23113301). The abstracts name the target variously as CCK receptors, central CCK1 receptors (2025) and a low-affinity blocker (2019); no binding affinity is in any abstract read.

Participants / model
Inbred and outbred mice and rats
Treatment
Intraperitoneal and oral GB-115
Follow-up
not stated in the source
Study design
Original preclinical studies
Funding
not stated in the source

Effects depend on the animal's emotional phenotype, and some groups showed none.

Read the original source
30-day rat study, withdrawal studies, mouse Porsolt test, four rhesus monkeys

Animal study

Kolik LG et al. Vestn Ross Akad Med Nauk. 2011(7):37-42. PMID 21899090.

In rats given 0.1 mg/kg intraperitoneally daily for 30 days, GB-115 kept its anxiolytic effect in the elevated plus-maze, and stopping it did not produce anxiety, aggression or lowered convulsive threshold, while stopping diazepam at 4.0 mg/kg/day did. In rats withdrawn from phenazepam or diazepam, GB-115 at 0.1 and 0.5 mg/kg intraperitoneally was anxiolytic 24 to 48 hours later (PMID 22238979). In mice, 0.025 mg/kg reduced immobility time in the Porsolt test, an effect smaller than amitriptyline at 10 mg/kg, with no change in spontaneous locomotor activity after acute dosing (PMID 21476266). In four male rhesus monkeys, 1 mg tablets for 7 days then 2 mg for 7 days reduced time in the upper part of the cage at 1 mg and the cortisol to DHEA-S ratio at 2 mg, with effects the authors call comparable to phenazepam; the monkeys received GB-115 first and phenazepam second, and no placebo is described (PMID 39847298).

Participants / model
Rats; mice; four male rhesus monkeys
Treatment
Intraperitoneal in rodents; oral tablets in monkeys
Follow-up
30 days of daily dosing in the rat tolerance study; 7 days at each dose in the monkeys
Study design
Original preclinical studies
Funding
not stated in the source

None of these abstracts measures sedation or vigilance directly, so keeps-alertness has only indirect animal support. The monkey study had no placebo described and a fixed order of drugs.

Read the original source
2007 design paper: Zakusov Institute analogues of CCK-4, GB-115 active in rats at 0.05 to 0.2 mg/kg

Animal study

Gudasheva TA et al. Bioorg Khim. 2007;33(4):413-20. PMID 17886432.

A 2007 design paper from Gudasheva, Kolik, Seredenin and colleagues made a series of dipeptide analogues of CCK-4 of the formula Ph(CH2)nCO-NH(CH2)mCO-Trp-NH2, based on the structure of CCK-4. GB-115, Ph(CH2)5CO-Gly-L-Trp-NH2, active in rats at 0.05 to 0.2 mg/kg after oral and intraperitoneal administration, was chosen for further study as a promising anxiolytic. A 2013 paper reports NMR work that identified a beta-turn, specifically a betaII-turn, as its biologically active conformation (PMID 24397028). Two review abstracts place GB-115 in the 'creation of dipeptide preparations' project of the V.V. Zakusov Institute of Pharmacology, Moscow, alongside noopept, dilept and GK-2, and call it a 'selective anxiolytic' and 'potential selective anxiolytic' (PMID 30295186, PMID 21899085).

Participants / model
Rats; chemical analogues
Treatment
Oral and intraperitoneal administration in rats
Follow-up
not stated in the source
Study design
Original preclinical and chemistry studies; review abstracts
Funding
not stated in the source

The work is from one institute and its collaborators.

Read the original source

How does GB-115 act on cholecystokinin signaling?

GB-115 is a retroanalogue of cholecystokinin-4 (CCK-4) designed from its structure. In rodents it prevented CCK-4-induced anxiety and did not prevent yohimbine-induced anxiety, so its developers conclude it shares a target with CCK-4, but the abstracts name that target in different ways and none gives a binding affinity.

A 2007 design paper made dipeptide analogues of CCK-4 of the formula Ph(CH2)nCO-NH(CH2)mCO-Trp-NH2, based on the structure of CCK-4, and chose GB-115 from the series. A 2013 paper reports NMR work that identified a betaII-turn as its biologically active conformation.

In rodents, activation of CCK-4 type 2 receptors abolished the antianxiety effect in BALB/c mice, and GB-115 prevented CCK-4-induced anxiety in C57Bl/6 mice and outbred rats but did not prevent yohimbine-induced anxiety. The authors conclude that CCK-4 and GB-115 share a pharmacological target.

The abstracts name the target variously as CCK receptors, central CCK1 receptors (2025) and a low-affinity blocker (2019), and no binding affinity is in any abstract read. The D-tryptophan version behaves as a CCK-4 agonist and is anxiogenic, which is why the stereochemistry matters. The mechanism is described by the institute that developed the compound and by its collaborators.

2007 design paper: Zakusov Institute analogues of CCK-4, GB-115 active in rats at 0.05 to 0.2 mg/kg

Animal study

Gudasheva TA et al. Bioorg Khim. 2007;33(4):413-20. PMID 17886432.

A 2007 design paper from Gudasheva, Kolik, Seredenin and colleagues made a series of dipeptide analogues of CCK-4 of the formula Ph(CH2)nCO-NH(CH2)mCO-Trp-NH2, based on the structure of CCK-4. GB-115, Ph(CH2)5CO-Gly-L-Trp-NH2, active in rats at 0.05 to 0.2 mg/kg after oral and intraperitoneal administration, was chosen for further study as a promising anxiolytic. A 2013 paper reports NMR work that identified a beta-turn, specifically a betaII-turn, as its biologically active conformation (PMID 24397028). Two review abstracts place GB-115 in the 'creation of dipeptide preparations' project of the V.V. Zakusov Institute of Pharmacology, Moscow, alongside noopept, dilept and GK-2, and call it a 'selective anxiolytic' and 'potential selective anxiolytic' (PMID 30295186, PMID 21899085).

Participants / model
Rats; chemical analogues
Treatment
Oral and intraperitoneal administration in rats
Follow-up
not stated in the source
Study design
Original preclinical and chemistry studies; review abstracts
Funding
not stated in the source

The work is from one institute and its collaborators.

Read the original source
Mice and rats: anxiolytic at 0.006 to 0.100 mg/kg intraperitoneally and 0.1 to 5.0 mg/kg orally; CCK-4 target

Animal study

Kolik LG et al. Bull Exp Biol Med. 2013;155(2):200-3. PMID 24130989.

In inbred mice and rats that differ in emotional stress response, GB-115 at 0.006 to 0.100 mg/kg dose-dependently raised open-field activity in BALB/c mice with no effect on C57Bl/6 mice, and at 0.025 and 0.05 mg/kg was anxiolytic in MR rats but not MNRA rats (PMID 12910281). Orally, anxiolytic effects appeared at 0.1 to 0.5 mg/kg in outbred mice, 0.1 and 5.0 mg/kg in BALB/c mice, and 0.5 to 0.7 mg/kg in outbred rats, which the authors describe as a shift from 0.006 to 0.100 mg/kg intraperitoneally to 0.1 to 5.0 mg/kg orally. Activation of CCK-4 type 2 receptors abolished the antianxiety effect in BALB/c mice, GB-115 prevented CCK-4-induced anxiety in C57Bl/6 mice and outbred rats and did not prevent yohimbine-induced anxiety, so the authors conclude CCK-4 and GB-115 share a pharmacological target (PMID 23113301). The abstracts name the target variously as CCK receptors, central CCK1 receptors (2025) and a low-affinity blocker (2019); no binding affinity is in any abstract read.

Participants / model
Inbred and outbred mice and rats
Treatment
Intraperitoneal and oral GB-115
Follow-up
not stated in the source
Study design
Original preclinical studies
Funding
not stated in the source

Effects depend on the animal's emotional phenotype, and some groups showed none.

Read the original source
PubChem: GB-115 identity, the L-tryptophan form, and the D-tryptophan flag

Chemical identity record

PubChem, National Library of Medicine. Compound summary for CID 11281948, N-[2-[[(2S)-1-amino-3-(1H-indol-3-yl)-1-oxopropan-2-yl]amino]-2-oxoethyl]-6-phenylhexanamide (GB-115).

GB-115 is PubChem CID 11281948, C25H30N4O3, 434.5 g/mol, CAS 678996-63-9 (listed among the synonyms), IUPAC name N-[2-[[(2S)-1-amino-3-(1H-indol-3-yl)-1-oxopropan-2-yl]amino]-2-oxoethyl]-6-phenylhexanamide, which is N-(6-phenylhexanoyl)glycyl-L-tryptophan amide. Synonyms include GB115, (-)-GB-115 and N-(1-Oxo-6-phenylhexyl)glycyl-L-tryptophanamide. The papers call it a dipeptide, a retroanalogue of cholecystokinin-4 (CCK-4) and a tripeptoid analog of CCK-4. Its Russian drug name is Ranquilon (the intervention name, with GB-115 as an other name, in the two ClinicalTrials.gov records). The D-tryptophan version is a different molecule with the opposite effect: the 2007 design paper says L-tryptophan derivatives were anxiolytic and D-tryptophan derivatives anxiogenic, and a 2023 paper calls D-GB-115 a CCK-4 agonist (PMID 37582869). One 2011 abstract writes GB-115 as Ph(CH2)5CO-Gly-D-Trp-NH2 (PMID 21476266), which conflicts with the 2007 definition and with PubChem.

Participants / model
Chemical identity, not a clinical population
Treatment
Defined molecule, free form (L-tryptophan amide)
Follow-up
Not applicable
Study design
Chemical database record; original reports
Funding
not stated in the source

Identity record only. This page uses the L-tryptophan form and treats the 2011 D-Trp formula as a probable error that is not resolved against the full text. A vendor vial labeled GB-115 cannot be tied to the L form by the name alone, and no public record ties any vendor material to the studied compound.

Read the original source

Has any spray form of GB-115 been studied?

No. A PubMed query on 10 October 2026 for the GB-115 name variants returned 23 records, and adding intranasal, spray, sublingual, nasal, buccal, transmucosal or transdermal terms returned none. Every studied form is oral or injected, so a spray has no pharmacokinetic, efficacy or safety source.

Research suppliers in the West sell GB-115 mainly as a spray. A PubMed query on 10 October 2026 for GB-115, GB115, GB 115 and the chemical names returned 23 records, and adding intranasal, spray, sublingual, nasal, buccal, transmucosal or transdermal returned 0 records.

Every dosage form in the abstracts is oral (tablets, micronized powder, crystalline substance) or intraperitoneal injection, and absolute oral bioavailability was 4.65% in one report, whose abstract does not give the species. The Russian product described on a drug reference page is a tablet, not a spray. A spray has no pharmacokinetic, efficacy or safety source in the records reviewed, so what a spray delivers is not known.

PubMed, 10 October 2026: 23 records, none on a spray form, none a published randomized trial

PubMed search record

PubMed search run 10 October 2026: "GB-115"[tiab] OR GB115[tiab] OR "GB 115"[tiab] and the chemical names, with follow-up queries adding intranasal, spray, sublingual, nasal, buccal, transmucosal or transdermal, and adding patients, volunteers, clinical, trial, human or humans.

The search returned 23 records, and the titles were read for all of them. Adding intranasal, spray, sublingual, nasal, buccal, transmucosal or transdermal returned 0 records. Every dosage form in the abstracts is oral (tablets, micronized powder, crystalline substance) or intraperitoneal injection, and oral bioavailability was 4.65%. A spray has no pharmacokinetic, efficacy or safety source in the records reviewed. Adding patients, volunteers, clinical, trial, human or humans returned 6 records (a conformation study, two review abstracts on development, the monkey study, the antidepressant mouse study and the Russian pilot); none is a published randomized controlled trial. The Phase 3 is registered with no posted results. Every paper read comes from the Zakusov Institute network or its collaborators, apart from a paramecium paper on D-GB-115 (PMID 37582869).

Participants / model
Records reviewed, not a population
Treatment
Not applicable
Follow-up
Searches run on 10 October 2026
Study design
Dated literature search
Funding
not stated in the source

An absence finding as of 10 October 2026, not proof that no unpublished or unindexed work exists.

Read the original source
Russian institute toxicology and bioavailability reports: no signal in the abstracts, 4.65% absolute bioavailability

Animal study

Sorokina AV et al. Eksp Klin Farmakol. 2010;73(6):29-32. PMID 20726348.

No animals were lost after acute oral doses up to 6000 mg/kg in mice and 3500 mg/kg in rats, 6 months of oral dosing at 0.1 and 10 mg/kg in rabbits and rats caused no irreversible pathological changes in organs and systems studied, and the dipeptide showed no allergenic, immunotoxic or mutagenic activity and no effect on generative function or on antenatal and postnatal development of progeny in these studies; at 10 mg/kg it suppressed the inflammatory response to concanavalin A. Absolute bioavailability was 4.65% and the dipeptide was resistant to peptidases (PMID 18457023; the species and route doses are not in the abstract). Micronized material gave better bioavailability than crystalline material in male rats (PMID 27017703), and one of three oral forms showed a relative bioequivalence of 192% versus micronized substance, the other two 53% and 117% (PMID 25322652).

Participants / model
Mice, rats and rabbits; male rats
Treatment
Oral GB-115
Follow-up
6 months of oral dosing in the chronic toxicity work
Study design
Original preclinical studies
Funding
not stated in the source

These are Russian institute reports, not a regulator review.

Read the original source
Secondary Russian reference page and trade news: Valenta Pharm prescription tablet, no registration number shown

Regulatory record

RLS (rlsnet.ru) drug reference page for Ranquilon (spelled Rankvilon in its address), and a trade news item dated 2024-12-13; DailyMed label search and openFDA Drugs@FDA query for GB-115, run 10 October 2026.

A Russian drug reference page for Ranquilon lists the holder as Valenta Pharm, 1 mg round tablets of N-(6-phenylhexanoyl)glycyl-L-tryptophan amide, prescription use, adults 18 and over, for anxiety states in neurasthenia and adjustment disorder, contraindicated in hypersensitivity and (in the page text) children under 18, pregnancy and breastfeeding. Adverse reactions listed with frequency unknown include irritability, insomnia, somnolence, daytime somnolence, headache, dizziness, attention impairment, tremor, taste disturbance, a reversible decrease in visual acuity, nausea, diarrhea, arthralgia, proteinuria and asthenia; the page carries an agreement date of 2024-12-23. A trade news item dated 2024-12-13 reports Valenta Pharm launched an original anxiety drug named Ranquilon (Russian spelling Rankvilon) from a price of 990 rubles and calls it the first of a new class of cholecystokinin receptor blockers (a company claim). Neither page shows a registration number or registration date. DailyMed returned no label for GB-115, and the openFDA Drugs@FDA query returned no match.

Participants / model
Records reviewed, not a population
Treatment
Oral 1 mg tablets (Russia)
Follow-up
Not applicable
Study design
Secondary drug-reference and trade pages, not the state register; dated label search
Funding
not stated in the source

Both pages are secondary, and neither shows a registration number or date, so no registration claim is made until the Russian state register is read. The reference page lists somnolence and attention impairment among adverse reactions, which bears on the keeps-alertness wording. The official label was not read.

Read the original source

Is GB-115 an anxiolytic that keeps alertness?

Partly. Rodent work supports an anxiolytic effect and a small uncontrolled Russian pilot reports a stimulating component and better attention, but no animal abstract measures sedation or vigilance directly, and a Russian reference page lists somnolence and attention impairment among reported adverse reactions. The spray form sold by research suppliers has no data behind it.

Sellers describe an anxiolytic that keeps alertness, sold mainly as a spray. The anxiolytic part is supported by rodent work from one institute network, with effects that depend on the animal's emotional phenotype. The alertness part is supported indirectly: no animal abstract measures sedation or vigilance, and the small uncontrolled Russian pilot reports stimulating properties and favorable changes in attention and reaction time.

A Russian drug reference page for the Ranquilon tablet lists somnolence, daytime somnolence and attention impairment among adverse reactions of unknown frequency, which bears on the keeps-alertness wording. The official label was not read.

The spray has no data of any kind behind it, because every studied form is oral or injected, and the vendor form is not the tablet that Russian sources describe. No published randomized controlled trial exists in the records reviewed.

Mice and rats: anxiolytic at 0.006 to 0.100 mg/kg intraperitoneally and 0.1 to 5.0 mg/kg orally; CCK-4 target

Animal study

Kolik LG et al. Bull Exp Biol Med. 2013;155(2):200-3. PMID 24130989.

In inbred mice and rats that differ in emotional stress response, GB-115 at 0.006 to 0.100 mg/kg dose-dependently raised open-field activity in BALB/c mice with no effect on C57Bl/6 mice, and at 0.025 and 0.05 mg/kg was anxiolytic in MR rats but not MNRA rats (PMID 12910281). Orally, anxiolytic effects appeared at 0.1 to 0.5 mg/kg in outbred mice, 0.1 and 5.0 mg/kg in BALB/c mice, and 0.5 to 0.7 mg/kg in outbred rats, which the authors describe as a shift from 0.006 to 0.100 mg/kg intraperitoneally to 0.1 to 5.0 mg/kg orally. Activation of CCK-4 type 2 receptors abolished the antianxiety effect in BALB/c mice, GB-115 prevented CCK-4-induced anxiety in C57Bl/6 mice and outbred rats and did not prevent yohimbine-induced anxiety, so the authors conclude CCK-4 and GB-115 share a pharmacological target (PMID 23113301). The abstracts name the target variously as CCK receptors, central CCK1 receptors (2025) and a low-affinity blocker (2019); no binding affinity is in any abstract read.

Participants / model
Inbred and outbred mice and rats
Treatment
Intraperitoneal and oral GB-115
Follow-up
not stated in the source
Study design
Original preclinical studies
Funding
not stated in the source

Effects depend on the animal's emotional phenotype, and some groups showed none.

Read the original source
Russian pilot in 31 patients and a 2022 poster analysis of 25 patients, no control group described

Human study

Neznamov GG et al. Zh Nevrol Psikhiatr Im S S Korsakova. 2019;119(8):53-60. PMID 31626171.

A Russian-language study in 31 patients with generalized anxiety disorder (22 women, 9 men, aged 22 to 53), given 1 mg tablets for 21 days, determined an effective dose of 6 mg per day and reported a fast-onset anxiolytic effect with 'stimulating properties', a beneficial effect on sleep disturbances and autonomic symptoms, favorable changes in attention parameters, reaction time and overall performance, and no initial overactivation, anxiety or sleep disturbance of the kind seen with SSRIs and SNRIs. The authors conclude it is safe and well tolerated. The abstract describes no control group, gives no scale scores and gives no adverse event counts. A European Congress of Psychiatry 2022 poster abstract from the Zakusov Institute analyzed 25 patients with GAD (8 men, 17 women, median age 34) given 6 mg daily for 21 days: median HARS total fell from 22 to 19, 13, 9 and 5 on days 3, 7, 14 and 21, and median MFI-20 fell from 70 to 59, 52, 37 and 28 (p < 0.001 for both); no patient had stimulation-related side effects, and the authors describe 'mild psychostimulant properties' (Eur Psychiatry 2022;65 Suppl 1:S388, DOI 10.1192/j.eurpsy.2022.981, no PMID).

Participants / model
Adults with generalized anxiety disorder (31 patients in the pilot, 25 in the poster analysis)
Treatment
Oral tablets, 1 mg tablets for 21 days in the pilot and 6 mg daily for 21 days in the poster analysis
Follow-up
21 days
Study design
Original uncontrolled clinical study as described in its abstract; conference poster abstract with a post-hoc analysis
Funding
not stated in the source

Seredenin SB is an author of the pilot. The poster is a post-hoc analysis that follows the pilot, with no comparator arm reported in its abstract. No control group, scale scores or adverse event counts are in the pilot abstract.

Read the original source
Secondary Russian reference page and trade news: Valenta Pharm prescription tablet, no registration number shown

Regulatory record

RLS (rlsnet.ru) drug reference page for Ranquilon (spelled Rankvilon in its address), and a trade news item dated 2024-12-13; DailyMed label search and openFDA Drugs@FDA query for GB-115, run 10 October 2026.

A Russian drug reference page for Ranquilon lists the holder as Valenta Pharm, 1 mg round tablets of N-(6-phenylhexanoyl)glycyl-L-tryptophan amide, prescription use, adults 18 and over, for anxiety states in neurasthenia and adjustment disorder, contraindicated in hypersensitivity and (in the page text) children under 18, pregnancy and breastfeeding. Adverse reactions listed with frequency unknown include irritability, insomnia, somnolence, daytime somnolence, headache, dizziness, attention impairment, tremor, taste disturbance, a reversible decrease in visual acuity, nausea, diarrhea, arthralgia, proteinuria and asthenia; the page carries an agreement date of 2024-12-23. A trade news item dated 2024-12-13 reports Valenta Pharm launched an original anxiety drug named Ranquilon (Russian spelling Rankvilon) from a price of 990 rubles and calls it the first of a new class of cholecystokinin receptor blockers (a company claim). Neither page shows a registration number or registration date. DailyMed returned no label for GB-115, and the openFDA Drugs@FDA query returned no match.

Participants / model
Records reviewed, not a population
Treatment
Oral 1 mg tablets (Russia)
Follow-up
Not applicable
Study design
Secondary drug-reference and trade pages, not the state register; dated label search
Funding
not stated in the source

Both pages are secondary, and neither shows a registration number or date, so no registration claim is made until the Russian state register is read. The reference page lists somnolence and attention impairment among adverse reactions, which bears on the keeps-alertness wording. The official label was not read.

Read the original source
PubMed, 10 October 2026: 23 records, none on a spray form, none a published randomized trial

PubMed search record

PubMed search run 10 October 2026: "GB-115"[tiab] OR GB115[tiab] OR "GB 115"[tiab] and the chemical names, with follow-up queries adding intranasal, spray, sublingual, nasal, buccal, transmucosal or transdermal, and adding patients, volunteers, clinical, trial, human or humans.

The search returned 23 records, and the titles were read for all of them. Adding intranasal, spray, sublingual, nasal, buccal, transmucosal or transdermal returned 0 records. Every dosage form in the abstracts is oral (tablets, micronized powder, crystalline substance) or intraperitoneal injection, and oral bioavailability was 4.65%. A spray has no pharmacokinetic, efficacy or safety source in the records reviewed. Adding patients, volunteers, clinical, trial, human or humans returned 6 records (a conformation study, two review abstracts on development, the monkey study, the antidepressant mouse study and the Russian pilot); none is a published randomized controlled trial. The Phase 3 is registered with no posted results. Every paper read comes from the Zakusov Institute network or its collaborators, apart from a paramecium paper on D-GB-115 (PMID 37582869).

Participants / model
Records reviewed, not a population
Treatment
Not applicable
Follow-up
Searches run on 10 October 2026
Study design
Dated literature search
Funding
not stated in the source

An absence finding as of 10 October 2026, not proof that no unpublished or unindexed work exists.

Read the original source

What is known about the safety of GB-115?

No controlled human safety data have been published. Russian toxicology reports in animals found no signal in the abstracts, and the pilot authors call GB-115 safe and well tolerated without giving adverse event counts. A Russian reference page lists contraindications in pregnancy, breastfeeding and under 18, and adverse reactions including somnolence, insomnia and attention impairment, and the identity and form of vendor material is not established.

In people, the pilot authors conclude GB-115 is safe and well tolerated, and the poster abstract reports no stimulation-related side effects, but neither gives adverse event counts and no controlled trial result is published or posted.

A Russian drug reference page lists contraindications in hypersensitivity, children under 18, pregnancy and breastfeeding. Adverse reactions listed with frequency unknown include irritability, insomnia, somnolence, daytime somnolence, headache, dizziness, attention impairment, tremor, taste disturbance, a reversible decrease in visual acuity, nausea, diarrhea, arthralgia, proteinuria and asthenia. The page is a secondary source and shows no registration number.

In Russian institute reports in animals, no animals were lost after acute oral doses up to 6000 mg/kg in mice and 3500 mg/kg in rats, and 6 months of oral dosing at 0.1 and 10 mg/kg in rabbits and rats caused no irreversible pathological changes in organs and systems studied. The dipeptide showed no allergenic, immunotoxic or mutagenic activity and no effect on generative function or on antenatal and postnatal development of progeny in these studies, and at 10 mg/kg it suppressed the inflammatory response to concanavalin A. These are institute reports, not a regulator review.

In one report the dipeptide was resistant to peptidases and absolute bioavailability was 4.65%, and the abstract does not give the species. Micronized material gave better bioavailability than crystalline material in male rats. No human half-life or human pharmacokinetic figure is established.

Product identity is a separate concern. The D-tryptophan form is a different molecule with the opposite effect, a vendor vial cannot be tied to the L form by the name alone, and no study tests a spray.

Secondary Russian reference page and trade news: Valenta Pharm prescription tablet, no registration number shown

Regulatory record

RLS (rlsnet.ru) drug reference page for Ranquilon (spelled Rankvilon in its address), and a trade news item dated 2024-12-13; DailyMed label search and openFDA Drugs@FDA query for GB-115, run 10 October 2026.

A Russian drug reference page for Ranquilon lists the holder as Valenta Pharm, 1 mg round tablets of N-(6-phenylhexanoyl)glycyl-L-tryptophan amide, prescription use, adults 18 and over, for anxiety states in neurasthenia and adjustment disorder, contraindicated in hypersensitivity and (in the page text) children under 18, pregnancy and breastfeeding. Adverse reactions listed with frequency unknown include irritability, insomnia, somnolence, daytime somnolence, headache, dizziness, attention impairment, tremor, taste disturbance, a reversible decrease in visual acuity, nausea, diarrhea, arthralgia, proteinuria and asthenia; the page carries an agreement date of 2024-12-23. A trade news item dated 2024-12-13 reports Valenta Pharm launched an original anxiety drug named Ranquilon (Russian spelling Rankvilon) from a price of 990 rubles and calls it the first of a new class of cholecystokinin receptor blockers (a company claim). Neither page shows a registration number or registration date. DailyMed returned no label for GB-115, and the openFDA Drugs@FDA query returned no match.

Participants / model
Records reviewed, not a population
Treatment
Oral 1 mg tablets (Russia)
Follow-up
Not applicable
Study design
Secondary drug-reference and trade pages, not the state register; dated label search
Funding
not stated in the source

Both pages are secondary, and neither shows a registration number or date, so no registration claim is made until the Russian state register is read. The reference page lists somnolence and attention impairment among adverse reactions, which bears on the keeps-alertness wording. The official label was not read.

Read the original source
Russian institute toxicology and bioavailability reports: no signal in the abstracts, 4.65% absolute bioavailability

Animal study

Sorokina AV et al. Eksp Klin Farmakol. 2010;73(6):29-32. PMID 20726348.

No animals were lost after acute oral doses up to 6000 mg/kg in mice and 3500 mg/kg in rats, 6 months of oral dosing at 0.1 and 10 mg/kg in rabbits and rats caused no irreversible pathological changes in organs and systems studied, and the dipeptide showed no allergenic, immunotoxic or mutagenic activity and no effect on generative function or on antenatal and postnatal development of progeny in these studies; at 10 mg/kg it suppressed the inflammatory response to concanavalin A. Absolute bioavailability was 4.65% and the dipeptide was resistant to peptidases (PMID 18457023; the species and route doses are not in the abstract). Micronized material gave better bioavailability than crystalline material in male rats (PMID 27017703), and one of three oral forms showed a relative bioequivalence of 192% versus micronized substance, the other two 53% and 117% (PMID 25322652).

Participants / model
Mice, rats and rabbits; male rats
Treatment
Oral GB-115
Follow-up
6 months of oral dosing in the chronic toxicity work
Study design
Original preclinical studies
Funding
not stated in the source

These are Russian institute reports, not a regulator review.

Read the original source
Russian pilot in 31 patients and a 2022 poster analysis of 25 patients, no control group described

Human study

Neznamov GG et al. Zh Nevrol Psikhiatr Im S S Korsakova. 2019;119(8):53-60. PMID 31626171.

A Russian-language study in 31 patients with generalized anxiety disorder (22 women, 9 men, aged 22 to 53), given 1 mg tablets for 21 days, determined an effective dose of 6 mg per day and reported a fast-onset anxiolytic effect with 'stimulating properties', a beneficial effect on sleep disturbances and autonomic symptoms, favorable changes in attention parameters, reaction time and overall performance, and no initial overactivation, anxiety or sleep disturbance of the kind seen with SSRIs and SNRIs. The authors conclude it is safe and well tolerated. The abstract describes no control group, gives no scale scores and gives no adverse event counts. A European Congress of Psychiatry 2022 poster abstract from the Zakusov Institute analyzed 25 patients with GAD (8 men, 17 women, median age 34) given 6 mg daily for 21 days: median HARS total fell from 22 to 19, 13, 9 and 5 on days 3, 7, 14 and 21, and median MFI-20 fell from 70 to 59, 52, 37 and 28 (p < 0.001 for both); no patient had stimulation-related side effects, and the authors describe 'mild psychostimulant properties' (Eur Psychiatry 2022;65 Suppl 1:S388, DOI 10.1192/j.eurpsy.2022.981, no PMID).

Participants / model
Adults with generalized anxiety disorder (31 patients in the pilot, 25 in the poster analysis)
Treatment
Oral tablets, 1 mg tablets for 21 days in the pilot and 6 mg daily for 21 days in the poster analysis
Follow-up
21 days
Study design
Original uncontrolled clinical study as described in its abstract; conference poster abstract with a post-hoc analysis
Funding
not stated in the source

Seredenin SB is an author of the pilot. The poster is a post-hoc analysis that follows the pilot, with no comparator arm reported in its abstract. No control group, scale scores or adverse event counts are in the pilot abstract.

Read the original source
PubChem: GB-115 identity, the L-tryptophan form, and the D-tryptophan flag

Chemical identity record

PubChem, National Library of Medicine. Compound summary for CID 11281948, N-[2-[[(2S)-1-amino-3-(1H-indol-3-yl)-1-oxopropan-2-yl]amino]-2-oxoethyl]-6-phenylhexanamide (GB-115).

GB-115 is PubChem CID 11281948, C25H30N4O3, 434.5 g/mol, CAS 678996-63-9 (listed among the synonyms), IUPAC name N-[2-[[(2S)-1-amino-3-(1H-indol-3-yl)-1-oxopropan-2-yl]amino]-2-oxoethyl]-6-phenylhexanamide, which is N-(6-phenylhexanoyl)glycyl-L-tryptophan amide. Synonyms include GB115, (-)-GB-115 and N-(1-Oxo-6-phenylhexyl)glycyl-L-tryptophanamide. The papers call it a dipeptide, a retroanalogue of cholecystokinin-4 (CCK-4) and a tripeptoid analog of CCK-4. Its Russian drug name is Ranquilon (the intervention name, with GB-115 as an other name, in the two ClinicalTrials.gov records). The D-tryptophan version is a different molecule with the opposite effect: the 2007 design paper says L-tryptophan derivatives were anxiolytic and D-tryptophan derivatives anxiogenic, and a 2023 paper calls D-GB-115 a CCK-4 agonist (PMID 37582869). One 2011 abstract writes GB-115 as Ph(CH2)5CO-Gly-D-Trp-NH2 (PMID 21476266), which conflicts with the 2007 definition and with PubChem.

Participants / model
Chemical identity, not a clinical population
Treatment
Defined molecule, free form (L-tryptophan amide)
Follow-up
Not applicable
Study design
Chemical database record; original reports
Funding
not stated in the source

Identity record only. This page uses the L-tryptophan form and treats the 2011 D-Trp formula as a probable error that is not resolved against the full text. A vendor vial labeled GB-115 cannot be tied to the L form by the name alone, and no public record ties any vendor material to the studied compound.

Read the original source

Why does GB-115 sit in C tier?

GB-115 has a documented development path, preclinical toxicology without a signal in the abstracts, a plausible CCK-related mechanism and a completed registered Phase 3 trial, but all published efficacy work comes from one institute network and the only human efficacy report is a small pilot with no control group in its abstract.

The development path is documented: an institute design paper from 2007, preclinical toxicology with no signal in the abstracts, a plausible CCK-related mechanism, a completed registered Phase 3 trial, and what looks like a marketed Russian prescription drug since late 2024.

The data are thin outside Russia. All published efficacy work comes from one institute network, the only human efficacy report is a small pilot with no control group in its abstract, no randomized result has been published or posted, oral bioavailability was 4.65% in one report, and no FDA label or application record was found. The abstracts also disagree on receptor subtype, and one writes the wrong stereochemistry. It does not reach a higher tier because the human outcomes are not independently shown, and it sits above the lowest tiers because nothing in the records reviewed shows a failed trial or documented harm.

2007 design paper: Zakusov Institute analogues of CCK-4, GB-115 active in rats at 0.05 to 0.2 mg/kg

Animal study

Gudasheva TA et al. Bioorg Khim. 2007;33(4):413-20. PMID 17886432.

A 2007 design paper from Gudasheva, Kolik, Seredenin and colleagues made a series of dipeptide analogues of CCK-4 of the formula Ph(CH2)nCO-NH(CH2)mCO-Trp-NH2, based on the structure of CCK-4. GB-115, Ph(CH2)5CO-Gly-L-Trp-NH2, active in rats at 0.05 to 0.2 mg/kg after oral and intraperitoneal administration, was chosen for further study as a promising anxiolytic. A 2013 paper reports NMR work that identified a beta-turn, specifically a betaII-turn, as its biologically active conformation (PMID 24397028). Two review abstracts place GB-115 in the 'creation of dipeptide preparations' project of the V.V. Zakusov Institute of Pharmacology, Moscow, alongside noopept, dilept and GK-2, and call it a 'selective anxiolytic' and 'potential selective anxiolytic' (PMID 30295186, PMID 21899085).

Participants / model
Rats; chemical analogues
Treatment
Oral and intraperitoneal administration in rats
Follow-up
not stated in the source
Study design
Original preclinical and chemistry studies; review abstracts
Funding
not stated in the source

The work is from one institute and its collaborators.

Read the original source
Russian pilot in 31 patients and a 2022 poster analysis of 25 patients, no control group described

Human study

Neznamov GG et al. Zh Nevrol Psikhiatr Im S S Korsakova. 2019;119(8):53-60. PMID 31626171.

A Russian-language study in 31 patients with generalized anxiety disorder (22 women, 9 men, aged 22 to 53), given 1 mg tablets for 21 days, determined an effective dose of 6 mg per day and reported a fast-onset anxiolytic effect with 'stimulating properties', a beneficial effect on sleep disturbances and autonomic symptoms, favorable changes in attention parameters, reaction time and overall performance, and no initial overactivation, anxiety or sleep disturbance of the kind seen with SSRIs and SNRIs. The authors conclude it is safe and well tolerated. The abstract describes no control group, gives no scale scores and gives no adverse event counts. A European Congress of Psychiatry 2022 poster abstract from the Zakusov Institute analyzed 25 patients with GAD (8 men, 17 women, median age 34) given 6 mg daily for 21 days: median HARS total fell from 22 to 19, 13, 9 and 5 on days 3, 7, 14 and 21, and median MFI-20 fell from 70 to 59, 52, 37 and 28 (p < 0.001 for both); no patient had stimulation-related side effects, and the authors describe 'mild psychostimulant properties' (Eur Psychiatry 2022;65 Suppl 1:S388, DOI 10.1192/j.eurpsy.2022.981, no PMID).

Participants / model
Adults with generalized anxiety disorder (31 patients in the pilot, 25 in the poster analysis)
Treatment
Oral tablets, 1 mg tablets for 21 days in the pilot and 6 mg daily for 21 days in the poster analysis
Follow-up
21 days
Study design
Original uncontrolled clinical study as described in its abstract; conference poster abstract with a post-hoc analysis
Funding
not stated in the source

Seredenin SB is an author of the pilot. The poster is a post-hoc analysis that follows the pilot, with no comparator arm reported in its abstract. No control group, scale scores or adverse event counts are in the pilot abstract.

Read the original source
Registered Russian Phase 3, 220 patients, placebo-controlled, no posted results; Phase 4 against afobazole

Trial registry record

ClinicalTrials.gov. NCT05586789. Randomized, quadruple-masked, placebo-controlled multicenter Phase 3 trial of Ranquilon (GB-115) tablets. Sponsor Valenta Pharm JSC, Russia. A second record, NCT06843044, is an open-label Phase 4 comparison with afobazole.

NCT05586789 is a randomized, quadruple-masked, placebo-controlled multicenter Phase 3 trial of Ranquilon 1 mg tablets (GB-115) at 6 mg per day for 28 days in 220 patients (actual) with anxiety in neurasthenia and adjustment disorders, sponsor Valenta Pharm JSC, Russia, ages 18 to 70; start 2022-10-12, completion 2023-01-03, last update 2023-07-27, no results posted as of 2026-10-10. The primary outcome is the proportion of patients with a 50% or greater reduction in Hamilton Anxiety Rating Scale score on day 29 plus or minus 1. A second record, NCT06843044, is an open-label Phase 4 comparison of Ranquilon 6 mg per day with afobazole (fabomotizole) 30 mg per day, 250 patients estimated, recruiting, start 2025-01-13, estimated completion 2027-12-31, last update 2025-07-08.

Participants / model
Adults 18 to 70 with anxiety in neurasthenia and adjustment disorders; 220 enrolled in the Phase 3 (actual), 250 estimated in the Phase 4
Treatment
Oral GB-115 (Ranquilon) tablets, 6 mg per day, against placebo for 28 days in the Phase 3 and against afobazole in the Phase 4
Follow-up
28 days in the Phase 3; start 2022-10-12, completion 2023-01-03
Study design
Phase 3 randomized, quadruple-masked, placebo-controlled multicenter trial; Phase 4 open-label comparison
Funding
Sponsor Valenta Pharm JSC, Russia (registry record)

The registry shows the trials were run and gives no outcome. No results are posted for the Phase 3, and the Phase 4 is recruiting. The Phase 3 result would need to be read again before this page is updated.

Read the original source
Secondary Russian reference page and trade news: Valenta Pharm prescription tablet, no registration number shown

Regulatory record

RLS (rlsnet.ru) drug reference page for Ranquilon (spelled Rankvilon in its address), and a trade news item dated 2024-12-13; DailyMed label search and openFDA Drugs@FDA query for GB-115, run 10 October 2026.

A Russian drug reference page for Ranquilon lists the holder as Valenta Pharm, 1 mg round tablets of N-(6-phenylhexanoyl)glycyl-L-tryptophan amide, prescription use, adults 18 and over, for anxiety states in neurasthenia and adjustment disorder, contraindicated in hypersensitivity and (in the page text) children under 18, pregnancy and breastfeeding. Adverse reactions listed with frequency unknown include irritability, insomnia, somnolence, daytime somnolence, headache, dizziness, attention impairment, tremor, taste disturbance, a reversible decrease in visual acuity, nausea, diarrhea, arthralgia, proteinuria and asthenia; the page carries an agreement date of 2024-12-23. A trade news item dated 2024-12-13 reports Valenta Pharm launched an original anxiety drug named Ranquilon (Russian spelling Rankvilon) from a price of 990 rubles and calls it the first of a new class of cholecystokinin receptor blockers (a company claim). Neither page shows a registration number or registration date. DailyMed returned no label for GB-115, and the openFDA Drugs@FDA query returned no match.

Participants / model
Records reviewed, not a population
Treatment
Oral 1 mg tablets (Russia)
Follow-up
Not applicable
Study design
Secondary drug-reference and trade pages, not the state register; dated label search
Funding
not stated in the source

Both pages are secondary, and neither shows a registration number or date, so no registration claim is made until the Russian state register is read. The reference page lists somnolence and attention impairment among adverse reactions, which bears on the keeps-alertness wording. The official label was not read.

Read the original source
Russian institute toxicology and bioavailability reports: no signal in the abstracts, 4.65% absolute bioavailability

Animal study

Sorokina AV et al. Eksp Klin Farmakol. 2010;73(6):29-32. PMID 20726348.

No animals were lost after acute oral doses up to 6000 mg/kg in mice and 3500 mg/kg in rats, 6 months of oral dosing at 0.1 and 10 mg/kg in rabbits and rats caused no irreversible pathological changes in organs and systems studied, and the dipeptide showed no allergenic, immunotoxic or mutagenic activity and no effect on generative function or on antenatal and postnatal development of progeny in these studies; at 10 mg/kg it suppressed the inflammatory response to concanavalin A. Absolute bioavailability was 4.65% and the dipeptide was resistant to peptidases (PMID 18457023; the species and route doses are not in the abstract). Micronized material gave better bioavailability than crystalline material in male rats (PMID 27017703), and one of three oral forms showed a relative bioequivalence of 192% versus micronized substance, the other two 53% and 117% (PMID 25322652).

Participants / model
Mice, rats and rabbits; male rats
Treatment
Oral GB-115
Follow-up
6 months of oral dosing in the chronic toxicity work
Study design
Original preclinical studies
Funding
not stated in the source

These are Russian institute reports, not a regulator review.

Read the original source

Studies and sources

PubChem: GB-115 identity, the L-tryptophan form, and the D-tryptophan flag

Chemical identity record

PubChem, National Library of Medicine. Compound summary for CID 11281948, N-[2-[[(2S)-1-amino-3-(1H-indol-3-yl)-1-oxopropan-2-yl]amino]-2-oxoethyl]-6-phenylhexanamide (GB-115).

GB-115 is PubChem CID 11281948, C25H30N4O3, 434.5 g/mol, CAS 678996-63-9 (listed among the synonyms), IUPAC name N-[2-[[(2S)-1-amino-3-(1H-indol-3-yl)-1-oxopropan-2-yl]amino]-2-oxoethyl]-6-phenylhexanamide, which is N-(6-phenylhexanoyl)glycyl-L-tryptophan amide. Synonyms include GB115, (-)-GB-115 and N-(1-Oxo-6-phenylhexyl)glycyl-L-tryptophanamide. The papers call it a dipeptide, a retroanalogue of cholecystokinin-4 (CCK-4) and a tripeptoid analog of CCK-4. Its Russian drug name is Ranquilon (the intervention name, with GB-115 as an other name, in the two ClinicalTrials.gov records). The D-tryptophan version is a different molecule with the opposite effect: the 2007 design paper says L-tryptophan derivatives were anxiolytic and D-tryptophan derivatives anxiogenic, and a 2023 paper calls D-GB-115 a CCK-4 agonist (PMID 37582869). One 2011 abstract writes GB-115 as Ph(CH2)5CO-Gly-D-Trp-NH2 (PMID 21476266), which conflicts with the 2007 definition and with PubChem.

Participants / model
Chemical identity, not a clinical population
Treatment
Defined molecule, free form (L-tryptophan amide)
Follow-up
Not applicable
Study design
Chemical database record; original reports
Funding
not stated in the source

Identity record only. This page uses the L-tryptophan form and treats the 2011 D-Trp formula as a probable error that is not resolved against the full text. A vendor vial labeled GB-115 cannot be tied to the L form by the name alone, and no public record ties any vendor material to the studied compound.

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2007 design paper: Zakusov Institute analogues of CCK-4, GB-115 active in rats at 0.05 to 0.2 mg/kg

Animal study

Gudasheva TA et al. Bioorg Khim. 2007;33(4):413-20. PMID 17886432.

A 2007 design paper from Gudasheva, Kolik, Seredenin and colleagues made a series of dipeptide analogues of CCK-4 of the formula Ph(CH2)nCO-NH(CH2)mCO-Trp-NH2, based on the structure of CCK-4. GB-115, Ph(CH2)5CO-Gly-L-Trp-NH2, active in rats at 0.05 to 0.2 mg/kg after oral and intraperitoneal administration, was chosen for further study as a promising anxiolytic. A 2013 paper reports NMR work that identified a beta-turn, specifically a betaII-turn, as its biologically active conformation (PMID 24397028). Two review abstracts place GB-115 in the 'creation of dipeptide preparations' project of the V.V. Zakusov Institute of Pharmacology, Moscow, alongside noopept, dilept and GK-2, and call it a 'selective anxiolytic' and 'potential selective anxiolytic' (PMID 30295186, PMID 21899085).

Participants / model
Rats; chemical analogues
Treatment
Oral and intraperitoneal administration in rats
Follow-up
not stated in the source
Study design
Original preclinical and chemistry studies; review abstracts
Funding
not stated in the source

The work is from one institute and its collaborators.

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Mice and rats: anxiolytic at 0.006 to 0.100 mg/kg intraperitoneally and 0.1 to 5.0 mg/kg orally; CCK-4 target

Animal study

Kolik LG et al. Bull Exp Biol Med. 2013;155(2):200-3. PMID 24130989.

In inbred mice and rats that differ in emotional stress response, GB-115 at 0.006 to 0.100 mg/kg dose-dependently raised open-field activity in BALB/c mice with no effect on C57Bl/6 mice, and at 0.025 and 0.05 mg/kg was anxiolytic in MR rats but not MNRA rats (PMID 12910281). Orally, anxiolytic effects appeared at 0.1 to 0.5 mg/kg in outbred mice, 0.1 and 5.0 mg/kg in BALB/c mice, and 0.5 to 0.7 mg/kg in outbred rats, which the authors describe as a shift from 0.006 to 0.100 mg/kg intraperitoneally to 0.1 to 5.0 mg/kg orally. Activation of CCK-4 type 2 receptors abolished the antianxiety effect in BALB/c mice, GB-115 prevented CCK-4-induced anxiety in C57Bl/6 mice and outbred rats and did not prevent yohimbine-induced anxiety, so the authors conclude CCK-4 and GB-115 share a pharmacological target (PMID 23113301). The abstracts name the target variously as CCK receptors, central CCK1 receptors (2025) and a low-affinity blocker (2019); no binding affinity is in any abstract read.

Participants / model
Inbred and outbred mice and rats
Treatment
Intraperitoneal and oral GB-115
Follow-up
not stated in the source
Study design
Original preclinical studies
Funding
not stated in the source

Effects depend on the animal's emotional phenotype, and some groups showed none.

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30-day rat study, withdrawal studies, mouse Porsolt test, four rhesus monkeys

Animal study

Kolik LG et al. Vestn Ross Akad Med Nauk. 2011(7):37-42. PMID 21899090.

In rats given 0.1 mg/kg intraperitoneally daily for 30 days, GB-115 kept its anxiolytic effect in the elevated plus-maze, and stopping it did not produce anxiety, aggression or lowered convulsive threshold, while stopping diazepam at 4.0 mg/kg/day did. In rats withdrawn from phenazepam or diazepam, GB-115 at 0.1 and 0.5 mg/kg intraperitoneally was anxiolytic 24 to 48 hours later (PMID 22238979). In mice, 0.025 mg/kg reduced immobility time in the Porsolt test, an effect smaller than amitriptyline at 10 mg/kg, with no change in spontaneous locomotor activity after acute dosing (PMID 21476266). In four male rhesus monkeys, 1 mg tablets for 7 days then 2 mg for 7 days reduced time in the upper part of the cage at 1 mg and the cortisol to DHEA-S ratio at 2 mg, with effects the authors call comparable to phenazepam; the monkeys received GB-115 first and phenazepam second, and no placebo is described (PMID 39847298).

Participants / model
Rats; mice; four male rhesus monkeys
Treatment
Intraperitoneal in rodents; oral tablets in monkeys
Follow-up
30 days of daily dosing in the rat tolerance study; 7 days at each dose in the monkeys
Study design
Original preclinical studies
Funding
not stated in the source

None of these abstracts measures sedation or vigilance directly, so keeps-alertness has only indirect animal support. The monkey study had no placebo described and a fixed order of drugs.

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Russian institute toxicology and bioavailability reports: no signal in the abstracts, 4.65% absolute bioavailability

Animal study

Sorokina AV et al. Eksp Klin Farmakol. 2010;73(6):29-32. PMID 20726348.

No animals were lost after acute oral doses up to 6000 mg/kg in mice and 3500 mg/kg in rats, 6 months of oral dosing at 0.1 and 10 mg/kg in rabbits and rats caused no irreversible pathological changes in organs and systems studied, and the dipeptide showed no allergenic, immunotoxic or mutagenic activity and no effect on generative function or on antenatal and postnatal development of progeny in these studies; at 10 mg/kg it suppressed the inflammatory response to concanavalin A. Absolute bioavailability was 4.65% and the dipeptide was resistant to peptidases (PMID 18457023; the species and route doses are not in the abstract). Micronized material gave better bioavailability than crystalline material in male rats (PMID 27017703), and one of three oral forms showed a relative bioequivalence of 192% versus micronized substance, the other two 53% and 117% (PMID 25322652).

Participants / model
Mice, rats and rabbits; male rats
Treatment
Oral GB-115
Follow-up
6 months of oral dosing in the chronic toxicity work
Study design
Original preclinical studies
Funding
not stated in the source

These are Russian institute reports, not a regulator review.

Read the original source
Russian pilot in 31 patients and a 2022 poster analysis of 25 patients, no control group described

Human study

Neznamov GG et al. Zh Nevrol Psikhiatr Im S S Korsakova. 2019;119(8):53-60. PMID 31626171.

A Russian-language study in 31 patients with generalized anxiety disorder (22 women, 9 men, aged 22 to 53), given 1 mg tablets for 21 days, determined an effective dose of 6 mg per day and reported a fast-onset anxiolytic effect with 'stimulating properties', a beneficial effect on sleep disturbances and autonomic symptoms, favorable changes in attention parameters, reaction time and overall performance, and no initial overactivation, anxiety or sleep disturbance of the kind seen with SSRIs and SNRIs. The authors conclude it is safe and well tolerated. The abstract describes no control group, gives no scale scores and gives no adverse event counts. A European Congress of Psychiatry 2022 poster abstract from the Zakusov Institute analyzed 25 patients with GAD (8 men, 17 women, median age 34) given 6 mg daily for 21 days: median HARS total fell from 22 to 19, 13, 9 and 5 on days 3, 7, 14 and 21, and median MFI-20 fell from 70 to 59, 52, 37 and 28 (p < 0.001 for both); no patient had stimulation-related side effects, and the authors describe 'mild psychostimulant properties' (Eur Psychiatry 2022;65 Suppl 1:S388, DOI 10.1192/j.eurpsy.2022.981, no PMID).

Participants / model
Adults with generalized anxiety disorder (31 patients in the pilot, 25 in the poster analysis)
Treatment
Oral tablets, 1 mg tablets for 21 days in the pilot and 6 mg daily for 21 days in the poster analysis
Follow-up
21 days
Study design
Original uncontrolled clinical study as described in its abstract; conference poster abstract with a post-hoc analysis
Funding
not stated in the source

Seredenin SB is an author of the pilot. The poster is a post-hoc analysis that follows the pilot, with no comparator arm reported in its abstract. No control group, scale scores or adverse event counts are in the pilot abstract.

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Registered Russian Phase 3, 220 patients, placebo-controlled, no posted results; Phase 4 against afobazole

Trial registry record

ClinicalTrials.gov. NCT05586789. Randomized, quadruple-masked, placebo-controlled multicenter Phase 3 trial of Ranquilon (GB-115) tablets. Sponsor Valenta Pharm JSC, Russia. A second record, NCT06843044, is an open-label Phase 4 comparison with afobazole.

NCT05586789 is a randomized, quadruple-masked, placebo-controlled multicenter Phase 3 trial of Ranquilon 1 mg tablets (GB-115) at 6 mg per day for 28 days in 220 patients (actual) with anxiety in neurasthenia and adjustment disorders, sponsor Valenta Pharm JSC, Russia, ages 18 to 70; start 2022-10-12, completion 2023-01-03, last update 2023-07-27, no results posted as of 2026-10-10. The primary outcome is the proportion of patients with a 50% or greater reduction in Hamilton Anxiety Rating Scale score on day 29 plus or minus 1. A second record, NCT06843044, is an open-label Phase 4 comparison of Ranquilon 6 mg per day with afobazole (fabomotizole) 30 mg per day, 250 patients estimated, recruiting, start 2025-01-13, estimated completion 2027-12-31, last update 2025-07-08.

Participants / model
Adults 18 to 70 with anxiety in neurasthenia and adjustment disorders; 220 enrolled in the Phase 3 (actual), 250 estimated in the Phase 4
Treatment
Oral GB-115 (Ranquilon) tablets, 6 mg per day, against placebo for 28 days in the Phase 3 and against afobazole in the Phase 4
Follow-up
28 days in the Phase 3; start 2022-10-12, completion 2023-01-03
Study design
Phase 3 randomized, quadruple-masked, placebo-controlled multicenter trial; Phase 4 open-label comparison
Funding
Sponsor Valenta Pharm JSC, Russia (registry record)

The registry shows the trials were run and gives no outcome. No results are posted for the Phase 3, and the Phase 4 is recruiting. The Phase 3 result would need to be read again before this page is updated.

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Secondary Russian reference page and trade news: Valenta Pharm prescription tablet, no registration number shown

Regulatory record

RLS (rlsnet.ru) drug reference page for Ranquilon (spelled Rankvilon in its address), and a trade news item dated 2024-12-13; DailyMed label search and openFDA Drugs@FDA query for GB-115, run 10 October 2026.

A Russian drug reference page for Ranquilon lists the holder as Valenta Pharm, 1 mg round tablets of N-(6-phenylhexanoyl)glycyl-L-tryptophan amide, prescription use, adults 18 and over, for anxiety states in neurasthenia and adjustment disorder, contraindicated in hypersensitivity and (in the page text) children under 18, pregnancy and breastfeeding. Adverse reactions listed with frequency unknown include irritability, insomnia, somnolence, daytime somnolence, headache, dizziness, attention impairment, tremor, taste disturbance, a reversible decrease in visual acuity, nausea, diarrhea, arthralgia, proteinuria and asthenia; the page carries an agreement date of 2024-12-23. A trade news item dated 2024-12-13 reports Valenta Pharm launched an original anxiety drug named Ranquilon (Russian spelling Rankvilon) from a price of 990 rubles and calls it the first of a new class of cholecystokinin receptor blockers (a company claim). Neither page shows a registration number or registration date. DailyMed returned no label for GB-115, and the openFDA Drugs@FDA query returned no match.

Participants / model
Records reviewed, not a population
Treatment
Oral 1 mg tablets (Russia)
Follow-up
Not applicable
Study design
Secondary drug-reference and trade pages, not the state register; dated label search
Funding
not stated in the source

Both pages are secondary, and neither shows a registration number or date, so no registration claim is made until the Russian state register is read. The reference page lists somnolence and attention impairment among adverse reactions, which bears on the keeps-alertness wording. The official label was not read.

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PubMed, 10 October 2026: 23 records, none on a spray form, none a published randomized trial

PubMed search record

PubMed search run 10 October 2026: "GB-115"[tiab] OR GB115[tiab] OR "GB 115"[tiab] and the chemical names, with follow-up queries adding intranasal, spray, sublingual, nasal, buccal, transmucosal or transdermal, and adding patients, volunteers, clinical, trial, human or humans.

The search returned 23 records, and the titles were read for all of them. Adding intranasal, spray, sublingual, nasal, buccal, transmucosal or transdermal returned 0 records. Every dosage form in the abstracts is oral (tablets, micronized powder, crystalline substance) or intraperitoneal injection, and oral bioavailability was 4.65%. A spray has no pharmacokinetic, efficacy or safety source in the records reviewed. Adding patients, volunteers, clinical, trial, human or humans returned 6 records (a conformation study, two review abstracts on development, the monkey study, the antidepressant mouse study and the Russian pilot); none is a published randomized controlled trial. The Phase 3 is registered with no posted results. Every paper read comes from the Zakusov Institute network or its collaborators, apart from a paramecium paper on D-GB-115 (PMID 37582869).

Participants / model
Records reviewed, not a population
Treatment
Not applicable
Follow-up
Searches run on 10 October 2026
Study design
Dated literature search
Funding
not stated in the source

An absence finding as of 10 October 2026, not proof that no unpublished or unindexed work exists.

Read the original source

Why is GB-115 (Ranquilon) in C tier?

C fits a compound with a documented development path: an institute design paper, preclinical toxicology without a signal in the abstracts, a plausible CCK-related mechanism, a completed registered Phase 3 trial and what appears to be a marketed Russian prescription tablet. The data are thin outside Russia: one institute network, a small uncontrolled human pilot, no published or posted randomized result, and no FDA label or application record.