PT-141
updated
PT-141, or bremelanotide, is the medicine in Vyleesi. It improved sexual-desire and distress scores in trials of premenopausal women with acquired, generalized HSDD. Nausea affected 40% of treated participants. Research in men is limited, and one often-cited erectile-dysfunction trial carries an expression of concern.
Melanocortin receptor agonist
- Vyleesi is a single-dose subcutaneous autoinjector
- The label does not indicate it for men, postmenopausal women, or performance enhancement
- The duration of benefit after a dose is unknown
Who is Vyleesi approved for?
The current label covers premenopausal women with acquired, generalized HSDD. Acquired means low desire developed after a period without the problem. Generalized means it occurs across types of stimulation, situations, and partners. The low desire must cause marked distress or interpersonal difficulty and must not be due to a coexisting medical or psychiatric condition, relationship problems, or a medication or drug.
The label explicitly excludes men, postmenopausal women, children, and sexual-performance enhancement.
Vyleesi label · acquired generalized HSDD
FDA prescribing information
Cosette Pharmaceuticals. VYLEESI (bremelanotide injection) prescribing information. Revised March 2024; DailyMed updated November 13, 2025.
Defines the narrow indication, excluded populations, product and timing limits, eight-week stopping rule, phase 3 efficacy and discontinuation data, blood-pressure, pigment and nausea warnings, oral-drug and naltrexone interactions, pregnancy guidance, receptor pharmacology, and unknown clinical mechanism.
- Participants / model
- Premenopausal women with acquired, generalized HSDD not explained by a condition, relationship problem, or drug
- Treatment
- Vyleesi 1.75 mg/0.3 mL single-dose subcutaneous autoinjector used as needed
- Follow-up
- Two 24-week placebo-controlled trials plus label summary of a 52-week open-label extension
- Study design
- Regulatory prescribing information
- Funding
- Sponsor regulatory program
The label is not evidence for men, postmenopausal women, performance enhancement, intranasal bremelanotide, or unverified vials.
Read the original sourceDid RECONNECT improve desire, distress, satisfying events, or all three?
The two identical 24-week RECONNECT trials randomized 1,267 women; 1,247 entered the safety analysis and 1,202 the modified efficacy analysis. Against placebo, the integrated mean difference was +0.35 points on the FSFI desire domain and -0.33 points on the low-desire distress item. Both coprimary endpoints were statistically significant.
| Endpoint | Integrated drug-placebo difference | What it means |
|---|---|---|
| FSFI desire domain | +0.35 points | Average improvement in the questionnaire score for sexual desire |
| FSDS-DAO item 13 | -0.33 points | Average reduction in distress specifically tied to low desire |
| Number of satisfying sexual events | No significant difference | A secondary event-count endpoint that did not separate from placebo |
A post hoc analysis of the percentage of encounters rated satisfying favored bremelanotide, but the prespecified count of satisfying events did not. Those are not interchangeable endpoints.
Most participants were from US sites, 85.6% were White, and mean age was 39.
RECONNECT · desire and distress endpoints
Two randomized double-blind placebo-controlled trials
Kingsberg SA et al. Obstetrics & Gynecology. 2019;134(5):899-908. doi:10.1097/AOG.0000000000003500. PMID: 31599840.
Among 1,267 randomized women, integrated bremelanotide-placebo differences were +0.35 on the FSFI desire domain and -0.33 on the low-desire distress item; the prespecified satisfying-event count did not significantly differ.
- Participants / model
- Premenopausal women with acquired generalized HSDD; mean age 39, 96.6% enrolled at US sites, 85.6% White
- Treatment
- Subcutaneous bremelanotide 1.75 mg as needed versus matching placebo
- Follow-up
- 24 weeks
- Study design
- Two identical phase 3 randomized double-blind placebo-controlled multicenter trials
- Funding
- Palatin Technologies; sponsor participated in design, conduct, analysis, reporting, and funding
Average questionnaire improvements were modest, and discontinuation was high. The trials mainly enrolled White women at US sites.
Read the original sourceVyleesi label · acquired generalized HSDD
FDA prescribing information
Cosette Pharmaceuticals. VYLEESI (bremelanotide injection) prescribing information. Revised March 2024; DailyMed updated November 13, 2025.
Defines the narrow indication, excluded populations, product and timing limits, eight-week stopping rule, phase 3 efficacy and discontinuation data, blood-pressure, pigment and nausea warnings, oral-drug and naltrexone interactions, pregnancy guidance, receptor pharmacology, and unknown clinical mechanism.
- Participants / model
- Premenopausal women with acquired, generalized HSDD not explained by a condition, relationship problem, or drug
- Treatment
- Vyleesi 1.75 mg/0.3 mL single-dose subcutaneous autoinjector used as needed
- Follow-up
- Two 24-week placebo-controlled trials plus label summary of a 52-week open-label extension
- Study design
- Regulatory prescribing information
- Funding
- Sponsor regulatory program
The label is not evidence for men, postmenopausal women, performance enhancement, intranasal bremelanotide, or unverified vials.
Read the original sourceHow many people stopped treatment?
All-cause premature discontinuation during the 24-week blinded phase was 40% versus 13% in Study 1 and 39% versus 25% in Study 2 for Vyleesi versus placebo. Across the pooled trials, adverse reactions caused discontinuation in 18% with Vyleesi and 2% with placebo. Nausea alone caused 8% to stop.
Of 856 core completers, 684 elected the 52-week open-label extension. About 40% of those entrants completed it. Entry required core completion and no serious adverse event, so the extension describes a selected, treatment-tolerant group without a placebo control.
The label says to discontinue Vyleesi after eight weeks if symptoms have not improved.
Vyleesi label · acquired generalized HSDD
FDA prescribing information
Cosette Pharmaceuticals. VYLEESI (bremelanotide injection) prescribing information. Revised March 2024; DailyMed updated November 13, 2025.
Defines the narrow indication, excluded populations, product and timing limits, eight-week stopping rule, phase 3 efficacy and discontinuation data, blood-pressure, pigment and nausea warnings, oral-drug and naltrexone interactions, pregnancy guidance, receptor pharmacology, and unknown clinical mechanism.
- Participants / model
- Premenopausal women with acquired, generalized HSDD not explained by a condition, relationship problem, or drug
- Treatment
- Vyleesi 1.75 mg/0.3 mL single-dose subcutaneous autoinjector used as needed
- Follow-up
- Two 24-week placebo-controlled trials plus label summary of a 52-week open-label extension
- Study design
- Regulatory prescribing information
- Funding
- Sponsor regulatory program
The label is not evidence for men, postmenopausal women, performance enhancement, intranasal bremelanotide, or unverified vials.
Read the original sourceRECONNECT extension · selected completers
Open-label uncontrolled extension
Simon JA et al. Obstetrics & Gynecology. 2019;134(5):909-917. doi:10.1097/AOG.0000000000003514. PMID: 31599847.
Of 856 core completers, 684 entered the 52-week open-label extension and about 40% completed it; adverse events and consent withdrawal were major reasons for discontinuation.
- Participants / model
- Core-phase completers without a serious adverse event who elected extension participation
- Treatment
- Open-label as-needed bremelanotide
- Follow-up
- 52 additional weeks, up to 76 weeks total for prior active-treatment participants
- Study design
- Uncontrolled open-label extension
- Funding
- Palatin Technologies
Selection of core completers and exclusion after serious adverse events create survivor bias; there was no extension placebo group.
Read the original sourceHow common were nausea, blood-pressure changes, and pigmentation?
Nausea occurred in 40% of Vyleesi-treated phase 3 participants versus about 1% with placebo. Thirteen percent needed an antiemetic and 8% stopped because of nausea. Flushing, injection-site reactions, headache, and vomiting were also common. The product transiently raises blood pressure and lowers heart rate after each dose.
| Risk | Label findings | Precautions |
|---|---|---|
| Blood pressure | Maximum mean rise about 6 mmHg systolic and 3 mmHg diastolic, peaking 2 to 4 hours; usually back to baseline within 12 hours | Contraindicated with uncontrolled hypertension or known cardiovascular disease; not recommended at high cardiovascular risk |
| Nausea | 40%; usually most prominent with the first injection, but can recur | Persistent or severe symptoms can end treatment |
| Focal hyperpigmentation | 1% with intermittent phase 3 use; much higher with consecutive daily exposure | Face, gingiva, and breasts can be affected; resolution was not confirmed in every patient; darker skin carried higher risk |
In a separate study of consecutive daily dosing, 38% developed focal hyperpigmentation after eight days and another 14% developed new changes during eight more days. This was more frequent use than the approved intermittent schedule; those rates should not be presented as the expected risk with labeled use.
Vyleesi label · acquired generalized HSDD
FDA prescribing information
Cosette Pharmaceuticals. VYLEESI (bremelanotide injection) prescribing information. Revised March 2024; DailyMed updated November 13, 2025.
Defines the narrow indication, excluded populations, product and timing limits, eight-week stopping rule, phase 3 efficacy and discontinuation data, blood-pressure, pigment and nausea warnings, oral-drug and naltrexone interactions, pregnancy guidance, receptor pharmacology, and unknown clinical mechanism.
- Participants / model
- Premenopausal women with acquired, generalized HSDD not explained by a condition, relationship problem, or drug
- Treatment
- Vyleesi 1.75 mg/0.3 mL single-dose subcutaneous autoinjector used as needed
- Follow-up
- Two 24-week placebo-controlled trials plus label summary of a 52-week open-label extension
- Study design
- Regulatory prescribing information
- Funding
- Sponsor regulatory program
The label is not evidence for men, postmenopausal women, performance enhancement, intranasal bremelanotide, or unverified vials.
Read the original sourceWhich medicines interact, and what about pregnancy?
Bremelanotide can slow gastric emptying and alter the rate or extent of absorption of oral medicines. That matters most when a quick oral effect is important. The label separately says to avoid oral naltrexone products used for alcohol or opioid addiction because Vyleesi can substantially reduce naltrexone exposure and treatment failure has serious consequences.
The label advises effective contraception and stopping Vyleesi if pregnancy is suspected. Human pregnancy data are insufficient to establish risk, while animal studies found fetal harm at exposures above the clinical setting. This is a warning and discontinuation issue, not a claim that pregnancy is a formal contraindication.
Vyleesi label · acquired generalized HSDD
FDA prescribing information
Cosette Pharmaceuticals. VYLEESI (bremelanotide injection) prescribing information. Revised March 2024; DailyMed updated November 13, 2025.
Defines the narrow indication, excluded populations, product and timing limits, eight-week stopping rule, phase 3 efficacy and discontinuation data, blood-pressure, pigment and nausea warnings, oral-drug and naltrexone interactions, pregnancy guidance, receptor pharmacology, and unknown clinical mechanism.
- Participants / model
- Premenopausal women with acquired, generalized HSDD not explained by a condition, relationship problem, or drug
- Treatment
- Vyleesi 1.75 mg/0.3 mL single-dose subcutaneous autoinjector used as needed
- Follow-up
- Two 24-week placebo-controlled trials plus label summary of a 52-week open-label extension
- Study design
- Regulatory prescribing information
- Funding
- Sponsor regulatory program
The label is not evidence for men, postmenopausal women, performance enhancement, intranasal bremelanotide, or unverified vials.
Read the original sourceDoes the label support a 45-to-90-minute peak or a four-to-six-hour window?
No. The label says the approved autoinjector is used at least 45 minutes before anticipated sexual activity. It also says the duration of efficacy after each dose is unknown and the optimal administration window has not been fully characterized. The 45-minute instruction is a minimum lead time, not a measured peak-effect claim.
Vyleesi contains 1.75 mg in 0.3 mL in a single-use subcutaneous autoinjector. Its trial results apply to that product, not to an intranasal spray or an unverified multi-dose vial.
Vyleesi label · acquired generalized HSDD
FDA prescribing information
Cosette Pharmaceuticals. VYLEESI (bremelanotide injection) prescribing information. Revised March 2024; DailyMed updated November 13, 2025.
Defines the narrow indication, excluded populations, product and timing limits, eight-week stopping rule, phase 3 efficacy and discontinuation data, blood-pressure, pigment and nausea warnings, oral-drug and naltrexone interactions, pregnancy guidance, receptor pharmacology, and unknown clinical mechanism.
- Participants / model
- Premenopausal women with acquired, generalized HSDD not explained by a condition, relationship problem, or drug
- Treatment
- Vyleesi 1.75 mg/0.3 mL single-dose subcutaneous autoinjector used as needed
- Follow-up
- Two 24-week placebo-controlled trials plus label summary of a 52-week open-label extension
- Study design
- Regulatory prescribing information
- Funding
- Sponsor regulatory program
The label is not evidence for men, postmenopausal women, performance enhancement, intranasal bremelanotide, or unverified vials.
Read the original sourceFDA chemistry · cyclic free-acid peptide
FDA chemistry review
US Food and Drug Administration. Chemistry Review for Vyleesi, NDA 210557. 2019.
Defines bremelanotide acetate as a synthetic cyclic heptapeptide with an acetylated amino terminus and free acid at the carboxyl terminus, and specifies the approved autoinjector composition.
- Participants / model
- Not applicable
- Treatment
- Vyleesi 1.75 mg/0.3 mL autoinjector
- Follow-up
- FDA review completed for 2019 approval
- Study design
- Regulatory chemistry and manufacturing review
Chemical identity and product composition do not establish clinical effect in an unstudied population or another product.
Read the original sourceWhat did the erectile-dysfunction studies in men find?
A small placebo-controlled crossover study tested subcutaneous PT-141 in 25 men with moderate-to-severe ED who reported an inadequate response to sildenafil. With visual sexual stimulation, objective RigiScan erectile responses improved at the tested 4 mg and 6 mg exposures. Nausea and headache were more frequent. This was a laboratory erectile-response study, not a Vyleesi libido trial or an approved male regimen.
The male studies tested different doses and routes from Vyleesi. They measured erectile response rather than the desire and distress outcomes used for its approval in women; they do not establish an approved male regimen.
Rosen study · 25 men with ED
Small placebo-controlled crossover study
Rosen RC et al. International Journal of Impotence Research. 2004;16(2):135-142. doi:10.1038/sj.ijir.3901200. PMID: 14999221.
In men reporting inadequate sildenafil response, subcutaneous PT-141 at tested exposures increased objective erectile response during visual sexual stimulation versus placebo; nausea and headache were common in the small evidence review.
- Participants / model
- 25 men with moderate-to-severe ED and self-reported inadequate response to sildenafil in the crossover cohort
- Treatment
- Single subcutaneous PT-141 exposures versus placebo with visual sexual stimulation
- Follow-up
- Acute laboratory assessments with observation to 24 hours
- Study design
- Placebo-controlled three-way crossover study
- Funding
- Palatin-associated authors.
The study measured erectile response in 25 men using doses different from Vyleesi. It did not measure treatment of low sexual desire.
Read the original sourceSafarinejad trial · expression of concern
Randomized double-blind placebo-controlled trial under editorial concern
Safarinejad MR, Hosseini SY. Journal of Urology. 2008;179(3):1066-1071. doi:10.1016/j.juro.2007.10.063. PMID: 18206919.
The study randomized 172 men to intranasal bremelanotide and 170 to placebo. It reported 51 positive clinical results (33.5%) versus 13 (8.5%); the abstract does not state the analyzed denominators behind those percentages.
- Participants / model
- 342 married Iranian men aged 28 to 59 with ED classified as sildenafil nonresponsive
- Treatment
- 10 mg intranasal bremelanotide versus intranasal placebo across at least 16 home attempts
- Follow-up
- Repeated at-home attempts; exact calendar duration not stated in the abstract
- Study design
- Randomized double-blind placebo-controlled study
The Journal of Urology issued an expression of concern in 2023. The result should not be treated as secure efficacy evidence.
Read the original sourceJournal notice · male trial concern
Journal editorial notice
Journal of Urology. Expression of Concern: Salvage of Sildenafil Failures With Bremelanotide. 2023. doi:10.1097/JU.0000000000003117. PMID: 36626345.
Formally marks the 2008 intranasal male bremelanotide paper with an expression of concern.
- Participants / model
- Not applicable
- Treatment
- Not applicable
- Follow-up
- Notice published January 2023
- Study design
- Editorial integrity notice
The journal has flagged concerns about the underlying paper. This notice is an expression of concern, not a retraction.
Read the original sourceWhat does the Chinese phase 1 record add?
A Chinese phase 1 record describes a single 1.75 mg abdominal subcutaneous dose in healthy women aged 18 to 45, with pharmacokinetics, safety and tolerability as planned outcomes. The public record posted no numerical results.
The public record contains no Russian controlled trial of bremelanotide adding a distinct population, formulation or outcome; unindexed records may exist.
China phase 1 · registry only
Chinese clinical trial registry record
ClinicalTrials.cn. Phase I clinical study of bremelanotide in healthy Chinese female subjects.
Describes a planned single-dose 1.75 mg subcutaneous pharmacokinetic, safety, and tolerability study in healthy Chinese women aged 18 to 45; the public record posts no numerical results.
- Participants / model
- Healthy Chinese women aged 18 to 45 meeting BMI and cardiovascular screening criteria
- Treatment
- Single abdominal subcutaneous bremelanotide 1.75 mg
- Follow-up
- Single-dose phase 1 study; result follow-up not posted in the cited record
- Study design
- Registry-only phase 1 pharmacokinetic and safety plan
The public Chinese-language record supplies design and eligibility details but no posted efficacy or comparative result.
Read the original sourceHow is PT-141 related to melanotan II?
Both bremelanotide and melanotan II are cyclic heptapeptides. FDA describes bremelanotide as Ac-Nle-cyclo-(Asp-His-D-Phe-Arg-Trp-Lys-OH), with a free carboxy terminus. PubChem records melanotan II as the related cyclic lactam with a terminal amide.
Bremelanotide has a free carboxy terminus; melanotan II has a terminal amide. They are separate molecules, and bremelanotide trials do not establish melanotan II efficacy or safety.
FDA chemistry · cyclic free-acid peptide
FDA chemistry review
US Food and Drug Administration. Chemistry Review for Vyleesi, NDA 210557. 2019.
Defines bremelanotide acetate as a synthetic cyclic heptapeptide with an acetylated amino terminus and free acid at the carboxyl terminus, and specifies the approved autoinjector composition.
- Participants / model
- Not applicable
- Treatment
- Vyleesi 1.75 mg/0.3 mL autoinjector
- Follow-up
- FDA review completed for 2019 approval
- Study design
- Regulatory chemistry and manufacturing review
Chemical identity and product composition do not establish clinical effect in an unstudied population or another product.
Read the original sourcePubChem · melanotan II is cyclic
NIH chemical identity record
National Center for Biotechnology Information. PubChem Compound Summary for CID 92432, Melanotan II.
Records melanotan II as a synthetic cyclic heptapeptide and gives the terminal-amide condensed sequence and distinct formula.
- Participants / model
- Not applicable
- Treatment
- Not applicable
- Study design
- Chemical identity database
This record establishes chemical structure; it contains no clinical efficacy results.
Read the original sourceHow does bremelanotide work?
Bremelanotide nonselectively activates melanocortin receptors, with MC1R and MC4R most relevant at therapeutic exposures. MC4R-expressing neurons occur across the central nervous system, while MC1R activation in melanocytes increases pigmentation. The label explicitly says the mechanism by which Vyleesi improves HSDD is unknown.
A rat experiment supports a central behavioral hypothesis: PT-141 increased solicitation in hormone-primed female rats without increasing lordosis or general motor activity. That is preclinical behavior, not proof of which receptor produces a woman's clinical benefit or how a man will respond.
Vyleesi label · acquired generalized HSDD
FDA prescribing information
Cosette Pharmaceuticals. VYLEESI (bremelanotide injection) prescribing information. Revised March 2024; DailyMed updated November 13, 2025.
Defines the narrow indication, excluded populations, product and timing limits, eight-week stopping rule, phase 3 efficacy and discontinuation data, blood-pressure, pigment and nausea warnings, oral-drug and naltrexone interactions, pregnancy guidance, receptor pharmacology, and unknown clinical mechanism.
- Participants / model
- Premenopausal women with acquired, generalized HSDD not explained by a condition, relationship problem, or drug
- Treatment
- Vyleesi 1.75 mg/0.3 mL single-dose subcutaneous autoinjector used as needed
- Follow-up
- Two 24-week placebo-controlled trials plus label summary of a 52-week open-label extension
- Study design
- Regulatory prescribing information
- Funding
- Sponsor regulatory program
The label is not evidence for men, postmenopausal women, performance enhancement, intranasal bremelanotide, or unverified vials.
Read the original sourceRat study · solicitation, not clinical desire
Randomized preclinical behavioral study
Pfaus JG et al. Proceedings of the National Academy of Sciences. 2004;101(27):10201-10204. PMID: 15226502.
In hormone-primed female rats, 100 and 200 micrograms/kg increased solicitation-related behaviors without increasing lordosis, pacing, or generalized movement.
- Participants / model
- Ovariectomized hormone-primed Long-Evans female rats
- Treatment
- Single subcutaneous PT-141 before behavioral testing versus saline
- Follow-up
- Acute 30-minute mating tests
- Study design
- Randomized preclinical dose-response behavioral experiments
- Funding
- Palatin supplied the compound.
Rat solicitation is a model of appetitive behavior and cannot establish human clinical mechanism or effect size.
Read the original sourceStudies and sources
Vyleesi label · acquired generalized HSDD
FDA prescribing information
Cosette Pharmaceuticals. VYLEESI (bremelanotide injection) prescribing information. Revised March 2024; DailyMed updated November 13, 2025.
Defines the narrow indication, excluded populations, product and timing limits, eight-week stopping rule, phase 3 efficacy and discontinuation data, blood-pressure, pigment and nausea warnings, oral-drug and naltrexone interactions, pregnancy guidance, receptor pharmacology, and unknown clinical mechanism.
- Participants / model
- Premenopausal women with acquired, generalized HSDD not explained by a condition, relationship problem, or drug
- Treatment
- Vyleesi 1.75 mg/0.3 mL single-dose subcutaneous autoinjector used as needed
- Follow-up
- Two 24-week placebo-controlled trials plus label summary of a 52-week open-label extension
- Study design
- Regulatory prescribing information
- Funding
- Sponsor regulatory program
The label is not evidence for men, postmenopausal women, performance enhancement, intranasal bremelanotide, or unverified vials.
Read the original sourceRECONNECT · desire and distress endpoints
Two randomized double-blind placebo-controlled trials
Kingsberg SA et al. Obstetrics & Gynecology. 2019;134(5):899-908. doi:10.1097/AOG.0000000000003500. PMID: 31599840.
Among 1,267 randomized women, integrated bremelanotide-placebo differences were +0.35 on the FSFI desire domain and -0.33 on the low-desire distress item; the prespecified satisfying-event count did not significantly differ.
- Participants / model
- Premenopausal women with acquired generalized HSDD; mean age 39, 96.6% enrolled at US sites, 85.6% White
- Treatment
- Subcutaneous bremelanotide 1.75 mg as needed versus matching placebo
- Follow-up
- 24 weeks
- Study design
- Two identical phase 3 randomized double-blind placebo-controlled multicenter trials
- Funding
- Palatin Technologies; sponsor participated in design, conduct, analysis, reporting, and funding
Average questionnaire improvements were modest, and discontinuation was high. The trials mainly enrolled White women at US sites.
Read the original sourceRECONNECT extension · selected completers
Open-label uncontrolled extension
Simon JA et al. Obstetrics & Gynecology. 2019;134(5):909-917. doi:10.1097/AOG.0000000000003514. PMID: 31599847.
Of 856 core completers, 684 entered the 52-week open-label extension and about 40% completed it; adverse events and consent withdrawal were major reasons for discontinuation.
- Participants / model
- Core-phase completers without a serious adverse event who elected extension participation
- Treatment
- Open-label as-needed bremelanotide
- Follow-up
- 52 additional weeks, up to 76 weeks total for prior active-treatment participants
- Study design
- Uncontrolled open-label extension
- Funding
- Palatin Technologies
Selection of core completers and exclusion after serious adverse events create survivor bias; there was no extension placebo group.
Read the original sourceRosen study · 25 men with ED
Small placebo-controlled crossover study
Rosen RC et al. International Journal of Impotence Research. 2004;16(2):135-142. doi:10.1038/sj.ijir.3901200. PMID: 14999221.
In men reporting inadequate sildenafil response, subcutaneous PT-141 at tested exposures increased objective erectile response during visual sexual stimulation versus placebo; nausea and headache were common in the small evidence review.
- Participants / model
- 25 men with moderate-to-severe ED and self-reported inadequate response to sildenafil in the crossover cohort
- Treatment
- Single subcutaneous PT-141 exposures versus placebo with visual sexual stimulation
- Follow-up
- Acute laboratory assessments with observation to 24 hours
- Study design
- Placebo-controlled three-way crossover study
- Funding
- Palatin-associated authors.
The study measured erectile response in 25 men using doses different from Vyleesi. It did not measure treatment of low sexual desire.
Read the original sourceSafarinejad trial · expression of concern
Randomized double-blind placebo-controlled trial under editorial concern
Safarinejad MR, Hosseini SY. Journal of Urology. 2008;179(3):1066-1071. doi:10.1016/j.juro.2007.10.063. PMID: 18206919.
The study randomized 172 men to intranasal bremelanotide and 170 to placebo. It reported 51 positive clinical results (33.5%) versus 13 (8.5%); the abstract does not state the analyzed denominators behind those percentages.
- Participants / model
- 342 married Iranian men aged 28 to 59 with ED classified as sildenafil nonresponsive
- Treatment
- 10 mg intranasal bremelanotide versus intranasal placebo across at least 16 home attempts
- Follow-up
- Repeated at-home attempts; exact calendar duration not stated in the abstract
- Study design
- Randomized double-blind placebo-controlled study
The Journal of Urology issued an expression of concern in 2023. The result should not be treated as secure efficacy evidence.
Read the original sourceJournal notice · male trial concern
Journal editorial notice
Journal of Urology. Expression of Concern: Salvage of Sildenafil Failures With Bremelanotide. 2023. doi:10.1097/JU.0000000000003117. PMID: 36626345.
Formally marks the 2008 intranasal male bremelanotide paper with an expression of concern.
- Participants / model
- Not applicable
- Treatment
- Not applicable
- Follow-up
- Notice published January 2023
- Study design
- Editorial integrity notice
The journal has flagged concerns about the underlying paper. This notice is an expression of concern, not a retraction.
Read the original sourceFDA chemistry · cyclic free-acid peptide
FDA chemistry review
US Food and Drug Administration. Chemistry Review for Vyleesi, NDA 210557. 2019.
Defines bremelanotide acetate as a synthetic cyclic heptapeptide with an acetylated amino terminus and free acid at the carboxyl terminus, and specifies the approved autoinjector composition.
- Participants / model
- Not applicable
- Treatment
- Vyleesi 1.75 mg/0.3 mL autoinjector
- Follow-up
- FDA review completed for 2019 approval
- Study design
- Regulatory chemistry and manufacturing review
Chemical identity and product composition do not establish clinical effect in an unstudied population or another product.
Read the original sourcePubChem · melanotan II is cyclic
NIH chemical identity record
National Center for Biotechnology Information. PubChem Compound Summary for CID 92432, Melanotan II.
Records melanotan II as a synthetic cyclic heptapeptide and gives the terminal-amide condensed sequence and distinct formula.
- Participants / model
- Not applicable
- Treatment
- Not applicable
- Study design
- Chemical identity database
This record establishes chemical structure; it contains no clinical efficacy results.
Read the original sourceChina phase 1 · registry only
Chinese clinical trial registry record
ClinicalTrials.cn. Phase I clinical study of bremelanotide in healthy Chinese female subjects.
Describes a planned single-dose 1.75 mg subcutaneous pharmacokinetic, safety, and tolerability study in healthy Chinese women aged 18 to 45; the public record posts no numerical results.
- Participants / model
- Healthy Chinese women aged 18 to 45 meeting BMI and cardiovascular screening criteria
- Treatment
- Single abdominal subcutaneous bremelanotide 1.75 mg
- Follow-up
- Single-dose phase 1 study; result follow-up not posted in the cited record
- Study design
- Registry-only phase 1 pharmacokinetic and safety plan
The public Chinese-language record supplies design and eligibility details but no posted efficacy or comparative result.
Read the original sourceRat study · solicitation, not clinical desire
Randomized preclinical behavioral study
Pfaus JG et al. Proceedings of the National Academy of Sciences. 2004;101(27):10201-10204. PMID: 15226502.
In hormone-primed female rats, 100 and 200 micrograms/kg increased solicitation-related behaviors without increasing lordosis, pacing, or generalized movement.
- Participants / model
- Ovariectomized hormone-primed Long-Evans female rats
- Treatment
- Single subcutaneous PT-141 before behavioral testing versus saline
- Follow-up
- Acute 30-minute mating tests
- Study design
- Randomized preclinical dose-response behavioral experiments
- Funding
- Palatin supplied the compound.
Rat solicitation is a model of appetitive behavior and cannot establish human clinical mechanism or effect size.
Read the original sourceWhy is PT-141 in A tier?
A tier reflects two phase 3 trials and approval for acquired, generalized HSDD in premenopausal women. Average improvements in desire and distress were modest; satisfying sexual-event counts did not improve significantly. Adverse reactions caused 18% to stop Vyleesi, compared with 2% on placebo.
read PT-141 in the reptides guide, chapter 40: 10 pages, free to read.