MID-35
MID-35 is an experimental D-peptide that inhibits myostatin-related signaling. Small mouse studies found local muscle growth, and a cancer-cachexia model also found better grip strength with MID-35 alone. The cited evidence contains no human administration, pharmacokinetic, or safety study.
experimental 16-residue retro-inverso myostatin-inhibitory D-peptide
- MID-35 is a 16-residue all-D retro-inverso peptide, not an approved myostatin medicine
- The original study used five mice and compared one locally injected tibialis anterior muscle with the opposite saline-treated muscle
- The original local-muscle study measured weight; a later cachexia experiment also found better grip strength in mice.
- Cell assays found inhibition of several TGF-beta-family ligands, not myostatin alone
- No cited human trial, human pharmacokinetic study, adverse-event denominator, or validated systemic route
What exactly is MID-35?
MID-35 is a 16-residue peptide made from D-amino acids in a retro-inverso arrangement, with two D-cyclohexylglycine residues and a C-terminal amide. PubChem records it as CID 163322647. The name describes a research molecule; it does not identify a licensed drug, authenticated commercial vial, or standardized formulation.
The reported sequence is D-Leu-D-Arg-D-Chg-D-Lys-D-Arg-D-Trp-D-Ile-D-Arg-D-Chg-D-Lys-D-Ile-D-Trp-D-Arg-D-Ile-D-Tyr-D-Trp-NH2. Retro-inverso design reverses residue order and stereochemistry to mimic side-chain presentation while resisting some proteases; that design concept is not human pharmacokinetic proof.
PubChem · MID-35 identity
Official chemical identity record
National Center for Biotechnology Information. PubChem CID 163322647.
The record identifies MID-35/Myostatin-IN-1 as a 16-residue D-peptide with formula C118H184N34O17, molecular weight 2350.9 g/mol, and CAS 2757831-08-4.
- Study design
- Chemical database record
Database identity is not approval, batch authentication, or evidence of biological equivalence.
Read the original sourceTakayama et al., original MID-35 discovery, 2022
Primary preclinical study
Takayama K, Hitachi K, Okamoto H, Saitoh M, Odagiri M, Ohfusa R, Shimada T, Taguchi A, Taniguchi A, Tsuchida K, Hayashi Y. Development of Myostatin Inhibitory d-Peptides to Enhance the Potency, Increasing Skeletal Muscle Mass in Mice. ACS medicinal chemistry letters. 2022. DOI 10.1021/acsmedchemlett.1c00705.
The discovery paper is PMID 35300091, DOI 10.1021/acsmedchemlett.1c00705. Its HEK293 reporter IC50 was 0.19±0.05 µM for myostatin, versus about 0.63 for GDF11, 0.89 for activin A, and 1.6 for TGF-beta1. Five young male mice received local MID-35 with contralateral saline control. At day 28, the treated tibialis anterior weighed 133±10% of control. A separate 400-minute isolated-protease experiment showed chemical stability, not in-vivo pharmacokinetics. The authors disclosed academic funding and commercial or intellectual-property interests.
- Participants / model
- HEK293 reporter cells; isolated bovine trypsin/chymotrypsin; five young male C57BL/6J mice for MID-35 and four for the parent-peptide comparator
- Treatment
- MID-35 in cell/protease assays and a single local 30 nmol tibialis-anterior injection versus contralateral saline
- Follow-up
- Reporter and 400-minute protease assays; mouse endpoint at day 28
- Study design
- Peptide optimization followed by cell assays, protease-resistance assays, and paired local-muscle mouse experiment
- Funding
- Japan Agency for Medical Research and Development and academic grants; patent and company interests disclosed
Is MID-35 specific to myostatin?
It inhibits myostatin signaling, but strict selectivity is not established. Related ligands were also inhibited, and activin-A findings differed between cell systems.
The discovery HEK293 reporter assay gave an IC50 of 0.19 ± 0.05 micromolar for myostatin, versus about 0.63 for GDF11, 0.89 for activin A and 1.6 for TGF-beta1. The later HepG2 assay found no activin-A inhibition under its conditions. Assay and concentration matter.
Takayama et al., original MID-35 discovery, 2022
Primary preclinical study
Takayama K, Hitachi K, Okamoto H, Saitoh M, Odagiri M, Ohfusa R, Shimada T, Taguchi A, Taniguchi A, Tsuchida K, Hayashi Y. Development of Myostatin Inhibitory d-Peptides to Enhance the Potency, Increasing Skeletal Muscle Mass in Mice. ACS medicinal chemistry letters. 2022. DOI 10.1021/acsmedchemlett.1c00705.
The discovery paper is PMID 35300091, DOI 10.1021/acsmedchemlett.1c00705. Its HEK293 reporter IC50 was 0.19±0.05 µM for myostatin, versus about 0.63 for GDF11, 0.89 for activin A, and 1.6 for TGF-beta1. Five young male mice received local MID-35 with contralateral saline control. At day 28, the treated tibialis anterior weighed 133±10% of control. A separate 400-minute isolated-protease experiment showed chemical stability, not in-vivo pharmacokinetics. The authors disclosed academic funding and commercial or intellectual-property interests.
- Participants / model
- HEK293 reporter cells; isolated bovine trypsin/chymotrypsin; five young male C57BL/6J mice for MID-35 and four for the parent-peptide comparator
- Treatment
- MID-35 in cell/protease assays and a single local 30 nmol tibialis-anterior injection versus contralateral saline
- Follow-up
- Reporter and 400-minute protease assays; mouse endpoint at day 28
- Study design
- Peptide optimization followed by cell assays, protease-resistance assays, and paired local-muscle mouse experiment
- Funding
- Japan Agency for Medical Research and Development and academic grants; patent and company interests disclosed
Combination with anamorelin in Lewis-lung-carcinoma cachexia, 2022
Primary preclinical study
Hanada K, Fukasawa K, Hinata H, Imai S, Takayama K, Hirai H, Ohfusa R, Hayashi Y, Itoh F. Combination therapy with anamorelin and a myostatin inhibitor is advantageous for cancer cachexia in a mouse model. Cancer science. 2022. DOI 10.1111/cas.15491.
Male mice with LLC tumors were studied in groups of six. MID-35 alone improved grip strength and gastrocnemius fiber area: healthy 1817.2±502.0, tumor/PBS 1415.3±504.7, and tumor/MID35 1658.4±424.3 µm². Monotherapy survival, body weight, tumor growth, and heart-weight ratio were null. Combination treatment with anamorelin had the largest muscle and grip signals, but survival p=.052 and tumor-volume p=.09 did not meet the stated p<.05 threshold. Some tissue analyses used fewer samples than the treatment groups, many endpoints were tested, and blinding was not described. In HepG2 reporter assays, MID-35 inhibited myostatin, GDF11, and TGF-beta but not activin A. PMID 35849084, DOI 10.1111/cas.15491.
- Participants / model
- Lewis lung carcinoma-bearing cancer-cachexia mice, six per group
- Treatment
- Local intramuscular MID-35, anamorelin, combination, or controls
- Follow-up
- Repeated treatment during an approximately three-week tumor-model experiment
- Study design
- Controlled multi-arm mouse cachexia study
- Funding
- Japanese grants with patent and company relationships disclosed
What did the first MID-35 mouse experiment show?
Five young male C57BL/6J mice received one local MID-35 injection into one tibialis anterior muscle while the contralateral muscle received saline. At day 28, the peptide-treated muscles weighed 133 ± 10 percent of their paired saline controls. The comparator parent peptide produced a smaller change in four mice.
Takayama et al., original MID-35 discovery, 2022
Primary preclinical study
Takayama K, Hitachi K, Okamoto H, Saitoh M, Odagiri M, Ohfusa R, Shimada T, Taguchi A, Taniguchi A, Tsuchida K, Hayashi Y. Development of Myostatin Inhibitory d-Peptides to Enhance the Potency, Increasing Skeletal Muscle Mass in Mice. ACS medicinal chemistry letters. 2022. DOI 10.1021/acsmedchemlett.1c00705.
The discovery paper is PMID 35300091, DOI 10.1021/acsmedchemlett.1c00705. Its HEK293 reporter IC50 was 0.19±0.05 µM for myostatin, versus about 0.63 for GDF11, 0.89 for activin A, and 1.6 for TGF-beta1. Five young male mice received local MID-35 with contralateral saline control. At day 28, the treated tibialis anterior weighed 133±10% of control. A separate 400-minute isolated-protease experiment showed chemical stability, not in-vivo pharmacokinetics. The authors disclosed academic funding and commercial or intellectual-property interests.
- Participants / model
- HEK293 reporter cells; isolated bovine trypsin/chymotrypsin; five young male C57BL/6J mice for MID-35 and four for the parent-peptide comparator
- Treatment
- MID-35 in cell/protease assays and a single local 30 nmol tibialis-anterior injection versus contralateral saline
- Follow-up
- Reporter and 400-minute protease assays; mouse endpoint at day 28
- Study design
- Peptide optimization followed by cell assays, protease-resistance assays, and paired local-muscle mouse experiment
- Funding
- Japan Agency for Medical Research and Development and academic grants; patent and company interests disclosed
Has it improved strength, or only muscle weight?
MID-35 alone improved grip strength and muscle-fiber area in a mouse cancer-cachexia model. Its monotherapy survival, body weight and tumor-growth results were neutral.
The Lewis-lung-carcinoma experiment used six mice per group. Gastrocnemius fiber area averaged 1,415 square micrometers with tumor plus vehicle and 1,658 with tumor plus MID-35, versus 1,817 in healthy mice. Several tissue analyses used fewer samples, and many endpoints were tested.
Adding anamorelin produced larger muscle and grip signals, but the reported survival p=.052 and tumor-volume p=.09 were nonsignificant under the paper’s stated threshold. They should not be presented as established survival or tumor benefits.
Iontophoresis increased local tibialis-anterior mass by about 25% in five mice per group; gastrocnemius mass and mean fiber area did not significantly change. Delivery fluorescence used a different model peptide, not intact MID-35.
A 2026 study reported persistent local hypertrophy and sphingolipid changes. The early S1P increase appeared in young and adult muscle, not aged muscle. Lasting muscle growth does not measure drug half-life.
Combination with anamorelin in Lewis-lung-carcinoma cachexia, 2022
Primary preclinical study
Hanada K, Fukasawa K, Hinata H, Imai S, Takayama K, Hirai H, Ohfusa R, Hayashi Y, Itoh F. Combination therapy with anamorelin and a myostatin inhibitor is advantageous for cancer cachexia in a mouse model. Cancer science. 2022. DOI 10.1111/cas.15491.
Male mice with LLC tumors were studied in groups of six. MID-35 alone improved grip strength and gastrocnemius fiber area: healthy 1817.2±502.0, tumor/PBS 1415.3±504.7, and tumor/MID35 1658.4±424.3 µm². Monotherapy survival, body weight, tumor growth, and heart-weight ratio were null. Combination treatment with anamorelin had the largest muscle and grip signals, but survival p=.052 and tumor-volume p=.09 did not meet the stated p<.05 threshold. Some tissue analyses used fewer samples than the treatment groups, many endpoints were tested, and blinding was not described. In HepG2 reporter assays, MID-35 inhibited myostatin, GDF11, and TGF-beta but not activin A. PMID 35849084, DOI 10.1111/cas.15491.
- Participants / model
- Lewis lung carcinoma-bearing cancer-cachexia mice, six per group
- Treatment
- Local intramuscular MID-35, anamorelin, combination, or controls
- Follow-up
- Repeated treatment during an approximately three-week tumor-model experiment
- Study design
- Controlled multi-arm mouse cachexia study
- Funding
- Japanese grants with patent and company relationships disclosed
Michiue et al., iontophoretic delivery, 2023
Primary preclinical study
Michiue K, Takayama K, Taniguchi A, Hayashi Y, Kogure K. Increasing Skeletal Muscle Mass in Mice by Non-Invasive Intramuscular Delivery of Myostatin Inhibitory Peptide by Iontophoresis. Pharmaceuticals (Basel, Switzerland). 2023. DOI 10.3390/ph16030397.
Five mice per group underwent repeated iontophoresis; at day 42 tibialis-anterior mass increased about 25%, while gastrocnemius mass and mean fiber cross-sectional area were not significantly changed. Fiber-distribution and MyoD/myogenin trends were also nonsignificant; Atrogin/MuRF expression did not uniformly move in the proposed anti-atrophy direction. Delivery fluorescence used WYIEWIKIQIWSKLRL, a different FITC-labeled peptide, not the exact all-D MID-35 sequence. The experiment supports a local delivery approach, not intact MID-35 systemic exposure or a human transdermal product. Electrical stimulation contributes biological effects. DOI 10.3390/ph16030397.
- Participants / model
- Male C57BL/6J mice, five per group
- Treatment
- Local iontophoresis delivery of MID-35 versus controls on days 0, 7, and 14
- Follow-up
- 42 days
- Study design
- Controlled local-delivery mouse study
- Funding
- Japanese academic grants; related patent and company interests disclosed
Morito et al., age and sphingolipid follow-up, 2026
Primary preclinical study
Morito K, Nishikawa N, Hitachi K, Tamaki R, Nishikawa M, Hayashi Y, Tsuchida K, Takayama K. Myostatin Inhibitory D‑Peptides Induce Skeletal Muscle Hypertrophy along with Alteration of Bioactive Sphingolipid Metabolism. ACS pharmacology & translational science. 2026. DOI 10.1021/acsptsci.6c00124.
The primary record reports young, adult, and aged mouse experiments after local administration, sustained hypertrophy up to twelve weeks, central nuclei and Pax7 observations, and changes in sphingolipid metabolism. The reported day-three S1P increase occurred in young and adult but not aged muscle. These results expand the animal mechanism and durability story, but do not demonstrate human strength, systemic safety, measured human residence time, or that S1P is required for hypertrophy. DOI 10.1021/acsptsci.6c00124.
- Participants / model
- Young, adult, and aged male mice; five per paired-treatment group
- Treatment
- Single local 2 nmol MID-35 treatment in one tibialis anterior versus contralateral saline
- Follow-up
- Endpoints from 14 days through 12 weeks
- Study design
- Paired local-muscle mouse durability and mechanism study
- Funding
- Japanese academic grants and disclosed intellectual-property interests
Did the 2023 photooxygenation paper test plain MID-35 as a human treatment?
The study attached a photosensitizing catalyst to a related MID-35-derived D-peptide and used near-infrared light to oxidatively inactivate myostatin in biochemical and cell systems. It tested no person and no unmodified MID-35 treatment.
Myostatin photooxygenation conjugate, 2023
Primary preclinical study
Okamoto H, Murano SA, Ikekawa K, Katsuyama M, Konno S, Taguchi A, Takayama K, Taniguchi A, Hayashi Y. Inactivation of myostatin by photooxygenation using functionalized d-peptides. RSC medicinal chemistry. 2023. DOI 10.1039/d2md00425a.
Researchers attached a photosensitizing catalyst to a related MID-35-derived D-peptide and used near-infrared light to inactivate myostatin in biochemical and cell systems. They did not test unmodified MID-35 or administer the conjugate to people. DOI 10.1039/D2MD00425A.
- Participants / model
- Purified-protein and cell experimental systems
- Treatment
- Photosensitizer-conjugated myostatin-binding D-peptides plus near-infrared light
- Follow-up
- Acute laboratory experiments
- Study design
- Chemical conjugation and biochemical/cell proof of concept
- Funding
- Japanese academic grants and disclosed intellectual-property interests
Is there a human half-life, systemic route, or safety profile?
No. The original paper found that MID-35 remained largely intact for 400 minutes in isolated bovine trypsin and chymotrypsin assays. That is protease-resistance screening, not absorption, distribution, metabolism, elimination, or a human half-life. The cited evidence contains no human adverse-event denominator, immunogenicity assessment, interaction study, reproductive study, cardiovascular evaluation, or validated systemic exposure.
Biodistribution, immunogenicity, broader TGF-beta-family activity, and uneven muscle effects have not been measured in people. No human event rate can be calculated.
Takayama et al., original MID-35 discovery, 2022
Primary preclinical study
Takayama K, Hitachi K, Okamoto H, Saitoh M, Odagiri M, Ohfusa R, Shimada T, Taguchi A, Taniguchi A, Tsuchida K, Hayashi Y. Development of Myostatin Inhibitory d-Peptides to Enhance the Potency, Increasing Skeletal Muscle Mass in Mice. ACS medicinal chemistry letters. 2022. DOI 10.1021/acsmedchemlett.1c00705.
The discovery paper is PMID 35300091, DOI 10.1021/acsmedchemlett.1c00705. Its HEK293 reporter IC50 was 0.19±0.05 µM for myostatin, versus about 0.63 for GDF11, 0.89 for activin A, and 1.6 for TGF-beta1. Five young male mice received local MID-35 with contralateral saline control. At day 28, the treated tibialis anterior weighed 133±10% of control. A separate 400-minute isolated-protease experiment showed chemical stability, not in-vivo pharmacokinetics. The authors disclosed academic funding and commercial or intellectual-property interests.
- Participants / model
- HEK293 reporter cells; isolated bovine trypsin/chymotrypsin; five young male C57BL/6J mice for MID-35 and four for the parent-peptide comparator
- Treatment
- MID-35 in cell/protease assays and a single local 30 nmol tibialis-anterior injection versus contralateral saline
- Follow-up
- Reporter and 400-minute protease assays; mouse endpoint at day 28
- Study design
- Peptide optimization followed by cell assays, protease-resistance assays, and paired local-muscle mouse experiment
- Funding
- Japan Agency for Medical Research and Development and academic grants; patent and company interests disclosed
Clinical records · no MID-35 human study
Clinical trial and literature records
ClinicalTrials.gov, PubMed, WHO ICTRP-linked records, and regulator records for MID-35 and its cited aliases.
The cited clinical and literature records include no human administration, pharmacokinetic, safety, strength, function, or body-composition study under MID-35, MID35, Myostatin-IN-1, or the published peptide sequence.
- Participants / model
- Clinical trial, biomedical literature, and regulator records
- Treatment
- MID-35
Is MID-35 approved or allowed in tested sport?
The cited regulatory and clinical records show no approved medicine or human trial. WADA's 2026 S4.3 section prohibits agents that modify myostatin function, including myostatin inhibitors, at all times. MID-35 is not named individually, so the anti-doping statement rests on its intended mechanism rather than a molecule-specific listing.
Clinical records · no MID-35 human study
Clinical trial and literature records
ClinicalTrials.gov, PubMed, WHO ICTRP-linked records, and regulator records for MID-35 and its cited aliases.
The cited clinical and literature records include no human administration, pharmacokinetic, safety, strength, function, or body-composition study under MID-35, MID35, Myostatin-IN-1, or the published peptide sequence.
- Participants / model
- Clinical trial, biomedical literature, and regulator records
- Treatment
- MID-35
WADA 2026 · myostatin-inhibitor class
Official anti-doping standard
World Anti-Doping Agency. The 2026 Prohibited List, effective 1 January 2026.
Section S4.3 prohibits agents modifying myostatin function, including myostatin inhibitors, at all times. MID-35 is not individually named.
- Participants / model
- Athletes subject to the World Anti-Doping Code
- Follow-up
- Calendar year 2026
- Study design
- Anti-doping prohibited list
- Funding
- World Anti-Doping Agency
MID-35 class placement follows the molecule's stated myostatin-inhibitory mechanism, not explicit naming in the list.
Read the original sourceTakayama et al., original MID-35 discovery, 2022
Primary preclinical study
Takayama K, Hitachi K, Okamoto H, Saitoh M, Odagiri M, Ohfusa R, Shimada T, Taguchi A, Taniguchi A, Tsuchida K, Hayashi Y. Development of Myostatin Inhibitory d-Peptides to Enhance the Potency, Increasing Skeletal Muscle Mass in Mice. ACS medicinal chemistry letters. 2022. DOI 10.1021/acsmedchemlett.1c00705.
The discovery paper is PMID 35300091, DOI 10.1021/acsmedchemlett.1c00705. Its HEK293 reporter IC50 was 0.19±0.05 µM for myostatin, versus about 0.63 for GDF11, 0.89 for activin A, and 1.6 for TGF-beta1. Five young male mice received local MID-35 with contralateral saline control. At day 28, the treated tibialis anterior weighed 133±10% of control. A separate 400-minute isolated-protease experiment showed chemical stability, not in-vivo pharmacokinetics. The authors disclosed academic funding and commercial or intellectual-property interests.
- Participants / model
- HEK293 reporter cells; isolated bovine trypsin/chymotrypsin; five young male C57BL/6J mice for MID-35 and four for the parent-peptide comparator
- Treatment
- MID-35 in cell/protease assays and a single local 30 nmol tibialis-anterior injection versus contralateral saline
- Follow-up
- Reporter and 400-minute protease assays; mouse endpoint at day 28
- Study design
- Peptide optimization followed by cell assays, protease-resistance assays, and paired local-muscle mouse experiment
- Funding
- Japan Agency for Medical Research and Development and academic grants; patent and company interests disclosed
What do the regional records add?
The cited Chinese and Russian records include no additional exact-MID-35 administration study. A 2023 Japanese conference record describes an obese-mouse muscle study but does not report enough results to assess it.
The conference record identifies an obese-mouse muscle study but reports no results. Studies of other myostatin inhibitors cannot supply MID-35 efficacy or adverse-event estimates.
Teranishi and colleagues, high-fat-diet mouse conference record, 2023
Conference record
Teranishi and colleagues, high-fat-diet mouse conference record, 2023. https://jglobal.jst.go.jp/en/detail?JGLOBAL_ID=202302224040213854
A Japanese Pharmaceutical Society 143rd-meeting record identifies a study of MID-35 and skeletal-muscle mass in high-fat-diet obese mice, abstract 28P1-am1-093S, but reports no study results.
The bibliographic record does not provide study results.
Read the original sourceClinicalTrials.gov · no exact-compound study
Clinical trial registry
ClinicalTrials.gov records for MID-35.
The cited ClinicalTrials.gov and PubMed records include no administered-human study under MID-35, MID35, or Myostatin-IN-1. They do not cover unregistered or differently coded experiments. Trials of other myostatin-pathway agents cannot supply MID-35-specific benefit or adverse-event estimates.
Read the original sourceChinese and Russian records · no additional MID-35 study
Literature and registry records
Chinese and Russian literature and registry records for MID-35.
The cited Chinese and Russian records include general myostatin literature, reagent listings, secondary summaries, and unrelated inhibitors, but no additional MID-35 clinical or preclinical administered-subject study.
- Participants / model
- Chinese- and Russian-language literature and registry records
Why does MID-35 remain D?
Small animal studies support local muscle growth and, in tumor-bearing mice, a grip-strength benefit. No human trial establishes muscle gain, useful function, exposure or safety.
The original discovery paper is PMID 35300091, DOI 10.1021/acsmedchemlett.1c00705. Five mice received the local intervention, and later studies with overlapping investigators remained preclinical.
Takayama et al., original MID-35 discovery, 2022
Primary preclinical study
Takayama K, Hitachi K, Okamoto H, Saitoh M, Odagiri M, Ohfusa R, Shimada T, Taguchi A, Taniguchi A, Tsuchida K, Hayashi Y. Development of Myostatin Inhibitory d-Peptides to Enhance the Potency, Increasing Skeletal Muscle Mass in Mice. ACS medicinal chemistry letters. 2022. DOI 10.1021/acsmedchemlett.1c00705.
The discovery paper is PMID 35300091, DOI 10.1021/acsmedchemlett.1c00705. Its HEK293 reporter IC50 was 0.19±0.05 µM for myostatin, versus about 0.63 for GDF11, 0.89 for activin A, and 1.6 for TGF-beta1. Five young male mice received local MID-35 with contralateral saline control. At day 28, the treated tibialis anterior weighed 133±10% of control. A separate 400-minute isolated-protease experiment showed chemical stability, not in-vivo pharmacokinetics. The authors disclosed academic funding and commercial or intellectual-property interests.
- Participants / model
- HEK293 reporter cells; isolated bovine trypsin/chymotrypsin; five young male C57BL/6J mice for MID-35 and four for the parent-peptide comparator
- Treatment
- MID-35 in cell/protease assays and a single local 30 nmol tibialis-anterior injection versus contralateral saline
- Follow-up
- Reporter and 400-minute protease assays; mouse endpoint at day 28
- Study design
- Peptide optimization followed by cell assays, protease-resistance assays, and paired local-muscle mouse experiment
- Funding
- Japan Agency for Medical Research and Development and academic grants; patent and company interests disclosed
Combination with anamorelin in Lewis-lung-carcinoma cachexia, 2022
Primary preclinical study
Hanada K, Fukasawa K, Hinata H, Imai S, Takayama K, Hirai H, Ohfusa R, Hayashi Y, Itoh F. Combination therapy with anamorelin and a myostatin inhibitor is advantageous for cancer cachexia in a mouse model. Cancer science. 2022. DOI 10.1111/cas.15491.
Male mice with LLC tumors were studied in groups of six. MID-35 alone improved grip strength and gastrocnemius fiber area: healthy 1817.2±502.0, tumor/PBS 1415.3±504.7, and tumor/MID35 1658.4±424.3 µm². Monotherapy survival, body weight, tumor growth, and heart-weight ratio were null. Combination treatment with anamorelin had the largest muscle and grip signals, but survival p=.052 and tumor-volume p=.09 did not meet the stated p<.05 threshold. Some tissue analyses used fewer samples than the treatment groups, many endpoints were tested, and blinding was not described. In HepG2 reporter assays, MID-35 inhibited myostatin, GDF11, and TGF-beta but not activin A. PMID 35849084, DOI 10.1111/cas.15491.
- Participants / model
- Lewis lung carcinoma-bearing cancer-cachexia mice, six per group
- Treatment
- Local intramuscular MID-35, anamorelin, combination, or controls
- Follow-up
- Repeated treatment during an approximately three-week tumor-model experiment
- Study design
- Controlled multi-arm mouse cachexia study
- Funding
- Japanese grants with patent and company relationships disclosed
Morito et al., age and sphingolipid follow-up, 2026
Primary preclinical study
Morito K, Nishikawa N, Hitachi K, Tamaki R, Nishikawa M, Hayashi Y, Tsuchida K, Takayama K. Myostatin Inhibitory D‑Peptides Induce Skeletal Muscle Hypertrophy along with Alteration of Bioactive Sphingolipid Metabolism. ACS pharmacology & translational science. 2026. DOI 10.1021/acsptsci.6c00124.
The primary record reports young, adult, and aged mouse experiments after local administration, sustained hypertrophy up to twelve weeks, central nuclei and Pax7 observations, and changes in sphingolipid metabolism. The reported day-three S1P increase occurred in young and adult but not aged muscle. These results expand the animal mechanism and durability story, but do not demonstrate human strength, systemic safety, measured human residence time, or that S1P is required for hypertrophy. DOI 10.1021/acsptsci.6c00124.
- Participants / model
- Young, adult, and aged male mice; five per paired-treatment group
- Treatment
- Single local 2 nmol MID-35 treatment in one tibialis anterior versus contralateral saline
- Follow-up
- Endpoints from 14 days through 12 weeks
- Study design
- Paired local-muscle mouse durability and mechanism study
- Funding
- Japanese academic grants and disclosed intellectual-property interests
ClinicalTrials.gov · no exact-compound study
Clinical trial registry
ClinicalTrials.gov records for MID-35.
The cited ClinicalTrials.gov and PubMed records include no administered-human study under MID-35, MID35, or Myostatin-IN-1. They do not cover unregistered or differently coded experiments. Trials of other myostatin-pathway agents cannot supply MID-35-specific benefit or adverse-event estimates.
Read the original sourceStudies and sources
PubChem · MID-35 identity
Official chemical identity record
National Center for Biotechnology Information. PubChem CID 163322647.
The record identifies MID-35/Myostatin-IN-1 as a 16-residue D-peptide with formula C118H184N34O17, molecular weight 2350.9 g/mol, and CAS 2757831-08-4.
- Study design
- Chemical database record
Database identity is not approval, batch authentication, or evidence of biological equivalence.
Read the original sourceTakayama et al., original MID-35 discovery, 2022
Primary preclinical study
Takayama K, Hitachi K, Okamoto H, Saitoh M, Odagiri M, Ohfusa R, Shimada T, Taguchi A, Taniguchi A, Tsuchida K, Hayashi Y. Development of Myostatin Inhibitory d-Peptides to Enhance the Potency, Increasing Skeletal Muscle Mass in Mice. ACS medicinal chemistry letters. 2022. DOI 10.1021/acsmedchemlett.1c00705.
The discovery paper is PMID 35300091, DOI 10.1021/acsmedchemlett.1c00705. Its HEK293 reporter IC50 was 0.19±0.05 µM for myostatin, versus about 0.63 for GDF11, 0.89 for activin A, and 1.6 for TGF-beta1. Five young male mice received local MID-35 with contralateral saline control. At day 28, the treated tibialis anterior weighed 133±10% of control. A separate 400-minute isolated-protease experiment showed chemical stability, not in-vivo pharmacokinetics. The authors disclosed academic funding and commercial or intellectual-property interests.
- Participants / model
- HEK293 reporter cells; isolated bovine trypsin/chymotrypsin; five young male C57BL/6J mice for MID-35 and four for the parent-peptide comparator
- Treatment
- MID-35 in cell/protease assays and a single local 30 nmol tibialis-anterior injection versus contralateral saline
- Follow-up
- Reporter and 400-minute protease assays; mouse endpoint at day 28
- Study design
- Peptide optimization followed by cell assays, protease-resistance assays, and paired local-muscle mouse experiment
- Funding
- Japan Agency for Medical Research and Development and academic grants; patent and company interests disclosed
Myostatin photooxygenation conjugate, 2023
Primary preclinical study
Okamoto H, Murano SA, Ikekawa K, Katsuyama M, Konno S, Taguchi A, Takayama K, Taniguchi A, Hayashi Y. Inactivation of myostatin by photooxygenation using functionalized d-peptides. RSC medicinal chemistry. 2023. DOI 10.1039/d2md00425a.
Researchers attached a photosensitizing catalyst to a related MID-35-derived D-peptide and used near-infrared light to inactivate myostatin in biochemical and cell systems. They did not test unmodified MID-35 or administer the conjugate to people. DOI 10.1039/D2MD00425A.
- Participants / model
- Purified-protein and cell experimental systems
- Treatment
- Photosensitizer-conjugated myostatin-binding D-peptides plus near-infrared light
- Follow-up
- Acute laboratory experiments
- Study design
- Chemical conjugation and biochemical/cell proof of concept
- Funding
- Japanese academic grants and disclosed intellectual-property interests
Michiue et al., iontophoretic delivery, 2023
Primary preclinical study
Michiue K, Takayama K, Taniguchi A, Hayashi Y, Kogure K. Increasing Skeletal Muscle Mass in Mice by Non-Invasive Intramuscular Delivery of Myostatin Inhibitory Peptide by Iontophoresis. Pharmaceuticals (Basel, Switzerland). 2023. DOI 10.3390/ph16030397.
Five mice per group underwent repeated iontophoresis; at day 42 tibialis-anterior mass increased about 25%, while gastrocnemius mass and mean fiber cross-sectional area were not significantly changed. Fiber-distribution and MyoD/myogenin trends were also nonsignificant; Atrogin/MuRF expression did not uniformly move in the proposed anti-atrophy direction. Delivery fluorescence used WYIEWIKIQIWSKLRL, a different FITC-labeled peptide, not the exact all-D MID-35 sequence. The experiment supports a local delivery approach, not intact MID-35 systemic exposure or a human transdermal product. Electrical stimulation contributes biological effects. DOI 10.3390/ph16030397.
- Participants / model
- Male C57BL/6J mice, five per group
- Treatment
- Local iontophoresis delivery of MID-35 versus controls on days 0, 7, and 14
- Follow-up
- 42 days
- Study design
- Controlled local-delivery mouse study
- Funding
- Japanese academic grants; related patent and company interests disclosed
Combination with anamorelin in Lewis-lung-carcinoma cachexia, 2022
Primary preclinical study
Hanada K, Fukasawa K, Hinata H, Imai S, Takayama K, Hirai H, Ohfusa R, Hayashi Y, Itoh F. Combination therapy with anamorelin and a myostatin inhibitor is advantageous for cancer cachexia in a mouse model. Cancer science. 2022. DOI 10.1111/cas.15491.
Male mice with LLC tumors were studied in groups of six. MID-35 alone improved grip strength and gastrocnemius fiber area: healthy 1817.2±502.0, tumor/PBS 1415.3±504.7, and tumor/MID35 1658.4±424.3 µm². Monotherapy survival, body weight, tumor growth, and heart-weight ratio were null. Combination treatment with anamorelin had the largest muscle and grip signals, but survival p=.052 and tumor-volume p=.09 did not meet the stated p<.05 threshold. Some tissue analyses used fewer samples than the treatment groups, many endpoints were tested, and blinding was not described. In HepG2 reporter assays, MID-35 inhibited myostatin, GDF11, and TGF-beta but not activin A. PMID 35849084, DOI 10.1111/cas.15491.
- Participants / model
- Lewis lung carcinoma-bearing cancer-cachexia mice, six per group
- Treatment
- Local intramuscular MID-35, anamorelin, combination, or controls
- Follow-up
- Repeated treatment during an approximately three-week tumor-model experiment
- Study design
- Controlled multi-arm mouse cachexia study
- Funding
- Japanese grants with patent and company relationships disclosed
Morito et al., age and sphingolipid follow-up, 2026
Primary preclinical study
Morito K, Nishikawa N, Hitachi K, Tamaki R, Nishikawa M, Hayashi Y, Tsuchida K, Takayama K. Myostatin Inhibitory D‑Peptides Induce Skeletal Muscle Hypertrophy along with Alteration of Bioactive Sphingolipid Metabolism. ACS pharmacology & translational science. 2026. DOI 10.1021/acsptsci.6c00124.
The primary record reports young, adult, and aged mouse experiments after local administration, sustained hypertrophy up to twelve weeks, central nuclei and Pax7 observations, and changes in sphingolipid metabolism. The reported day-three S1P increase occurred in young and adult but not aged muscle. These results expand the animal mechanism and durability story, but do not demonstrate human strength, systemic safety, measured human residence time, or that S1P is required for hypertrophy. DOI 10.1021/acsptsci.6c00124.
- Participants / model
- Young, adult, and aged male mice; five per paired-treatment group
- Treatment
- Single local 2 nmol MID-35 treatment in one tibialis anterior versus contralateral saline
- Follow-up
- Endpoints from 14 days through 12 weeks
- Study design
- Paired local-muscle mouse durability and mechanism study
- Funding
- Japanese academic grants and disclosed intellectual-property interests
Clinical records · no MID-35 human study
Clinical trial and literature records
ClinicalTrials.gov, PubMed, WHO ICTRP-linked records, and regulator records for MID-35 and its cited aliases.
The cited clinical and literature records include no human administration, pharmacokinetic, safety, strength, function, or body-composition study under MID-35, MID35, Myostatin-IN-1, or the published peptide sequence.
- Participants / model
- Clinical trial, biomedical literature, and regulator records
- Treatment
- MID-35
WADA 2026 · myostatin-inhibitor class
Official anti-doping standard
World Anti-Doping Agency. The 2026 Prohibited List, effective 1 January 2026.
Section S4.3 prohibits agents modifying myostatin function, including myostatin inhibitors, at all times. MID-35 is not individually named.
- Participants / model
- Athletes subject to the World Anti-Doping Code
- Follow-up
- Calendar year 2026
- Study design
- Anti-doping prohibited list
- Funding
- World Anti-Doping Agency
MID-35 class placement follows the molecule's stated myostatin-inhibitory mechanism, not explicit naming in the list.
Read the original sourceChinese and Russian records · no additional MID-35 study
Literature and registry records
Chinese and Russian literature and registry records for MID-35.
The cited Chinese and Russian records include general myostatin literature, reagent listings, secondary summaries, and unrelated inhibitors, but no additional MID-35 clinical or preclinical administered-subject study.
- Participants / model
- Chinese- and Russian-language literature and registry records
Teranishi and colleagues, high-fat-diet mouse conference record, 2023
Conference record
Teranishi and colleagues, high-fat-diet mouse conference record, 2023. https://jglobal.jst.go.jp/en/detail?JGLOBAL_ID=202302224040213854
A Japanese Pharmaceutical Society 143rd-meeting record identifies a study of MID-35 and skeletal-muscle mass in high-fat-diet obese mice, abstract 28P1-am1-093S, but reports no study results.
The bibliographic record does not provide study results.
Read the original sourceClinicalTrials.gov · no exact-compound study
Clinical trial registry
ClinicalTrials.gov records for MID-35.
The cited ClinicalTrials.gov and PubMed records include no administered-human study under MID-35, MID35, or Myostatin-IN-1. They do not cover unregistered or differently coded experiments. Trials of other myostatin-pathway agents cannot supply MID-35-specific benefit or adverse-event estimates.
Read the original sourceWhy is MID-35 in D tier?
D: local muscle growth and better grip strength in small mouse studies. Human muscle gain, delivery, PK and safety remain unknown. The cachexia study’s survival and tumor-volume trends were nonsignificant.