BMS-564929

Overview

BMS-564929 (development code PS-178990) is a nonsteroidal selective androgen receptor modulator (SARM) of the bicyclic hydantoin class — specifically a pyrrolo[1,2-c]imidazole-1,3-dione chemotype. It is a true SARM — it is NOT a peptide and NOT a steroid. It appears in this peptide reference because it is discussed and stacked alongside peptides in the fitness and "research chemical" community, not because it is one.

BMS-564929 was originated by Bristol-Myers Squibb and intended for age-related androgen decline in men ("andropause"). Its published characterization is preclinical: in castrated male rats it is a subnanomolar androgen-receptor agonist (Ki ~2.11 nM) with extreme muscle-versus-prostate tissue selectivity — the property that made it interesting as an oral anabolic. The same primary study, however, flags a critical liability: it potently suppresses luteinizing hormone (LH), giving a narrow therapeutic index for suppression of the hypothalamic-pituitary-gonadal (HPG) axis.

Chemistry and structure

BMS-564929 is a nonsteroidal bicyclic-hydantoin small molecule, not an amino-acid chain and not a steroid nucleus. Its IUPAC name is 2-chloro-3-methyl-4-[(7R,7aS)-7-hydroxy- 1,3-dioxo-5,6,7,7a-tetrahydropyrrolo[1,2-c]imidazol-2-yl]benzonitrile (InChIKey KEJORAMIZFOODM-PWSUYJOCSA-N).

Mechanism of action

• Androgen receptor (AR) agonist. BMS-564929 binds the androgen receptor (AR, NR3C4) with subnanomolar affinity (Ki ~2.11 nM) and acts as a subnanomolar functional agonist in vitro, with high selectivity for AR over other steroid hormone receptors. It is not a peptide and not a steroid. [In vitro]
• Muscle-versus-prostate tissue selectivity. In castrated male rats it potently stimulates levator ani muscle growth (reported substantially more potent than testosterone) while sparing the prostate — approximately 160-fold muscle-over-prostate selectivity; cell-based assays show roughly 20-fold myoblast-over-prostate-cell selectivity. The selectivity is attributed to a distinct ligand-binding pocket (interaction with the F764 side chain, loss of the T877 hydrogen bond seen with DHT), producing differential coregulator recruitment. [Animal] [In vitro]
• HPG axis / luteinizing-hormone suppression (the key liability). BMS-564929 potently suppresses LH, defining a narrow therapeutic index with respect to gonadotropin / HPG-axis suppression — the principal preclinical liability limiting its therapeutic window. [Animal]
• No significant SHBG or aromatase interaction. It is reported to have no meaningful interaction with sex hormone-binding globulin (SHBG) and to not be a substrate for aromatase — i.e. not converted to estrogen — unlike testosterone. [In vitro]

Research and evidence

The published evidence base is preclinical (rat and in-vitro). There is no registered human trial of BMS-564929 for any indication, and no verifiable human efficacy, safety, or pharmacokinetic dataset.

Human evidence in context. There is none that is verifiable. ClinicalTrials.gov returns zero registered trials, so there are no completed human studies establishing efficacy for andropause, muscle growth, or any indication. The anabolic and selectivity claims rest on rat studies; the binding data are in vitro. Human pharmacokinetics — half-life, bioavailability, and metabolism — are not established in primary human sources; the ~8-14 h oral half-life is a secondary-database figure (DrugBank) with no corroborating peer-reviewed human PK publication, and should be treated as unverified.

Status and regulation

• Regulatory approval: None. BMS-564929 is not approved by the FDA, the EMA, or any other regulator for any indication. Its highest verifiable phase is preclinical — no registered human trial was found on ClinicalTrials.gov. Secondary sources (Wikipedia, DrugBank) assert "early human clinical trials," but this claim is uncited and unverified.
• Originator / development history: Originated by Bristol-Myers Squibb (alt code PS-178990). A downstream note associates the program with Pharmacopeia, but this hand-off was not corroborated in the sources reviewed here — treat it as UNVERIFIED.
• Anti-doping: Prohibited by the World Anti-Doping Agency (WADA) at all times (in- and out-of-competition), under Anabolic Agents — Other Anabolic Agents (SARMs), S1.2. WADA sport-eligibility is a separate axis from legality.
• Market reality: It is sold only as a "research chemical" / grey-market compound. Such products are of unknown identity, purity, and potency (see Safety, below).

Safety

No verifiable human safety data. Because BMS-564929 has no registered human trial, there is no verifiable human safety, tolerability, or pharmacokinetic dataset. Any "well-tolerated"-type framing from secondary sources is unsupported. Hepatotoxicity specific to BMS-564929 is not established — only the class-level FDA liver-injury warning is a human-relevant signal. Long-term consequences of SARM exposure in humans are not characterized, and this is compounded here by the absence of any human data. [Hypothesis] The overall picture: BMS-564929 has a known, compound-specific LH-suppression signal in animals, sits within a drug class the FDA has flagged for liver injury and testosterone suppression, and — as an unregulated research chemical — carries the additional, separate hazards of contamination and mislabeling.

Legal status

How it compares

BMS-564929 is often grouped with other SARMs and "recomposition" research chemicals, but each has its own distinct profile and none is an approved physique/performance drug:

• Ostarine (MK-2866) — the most-studied SARM and the closest clinical reference point: it actually reached human Phase 3 trials (in cancer muscle wasting) before failing its endpoints and gaining no approval. BMS-564929, by contrast, has no verifiable human trial at all — its profile is entirely preclinical/rat.
• Testolone (RAD-140) — another nonsteroidal SARM marketed for muscle growth; like BMS-564929 it is unapproved, WADA-prohibited, and carries the class-level FDA liver-injury and testosterone-suppression signals.

The honest framing: BMS-564929 is a preclinical, unapproved research reagent with a subnanomolar-agonist, muscle-selective profile in rats but a compound-specific LH-suppression liability and class-wide FDA-flagged risks — it is not a "milder, safer, or legal alternative to steroids," and its "human trial" reputation rests on an uncited, unverified claim. See the muscle growth & hormone overview.

Common misconceptions

• "BMS-564929 is a peptide." No. It is a nonsteroidal bicyclic-hydantoin small molecule (C14H12ClN3O3, 305.71 g/mol). It is not a peptide and not a steroid. It is covered here only because it is discussed and stacked with peptides.
• "It has been through early human clinical trials." Unverified. ClinicalTrials.gov returns zero registered studies; the "early human clinical trials" line is uncited and appears only in secondary sources (Wikipedia/DrugBank/blogs). The pharmacology it points to is preclinical rat work.
• "Its half-life is about 8-14 hours." That figure comes from a secondary database with no corroborating human pharmacokinetic publication and no registered human trial. Treat it as unverified, not established.
• "It's super-selective, so it's a safe, legal alternative to steroids." No. The muscle-selectivity is a rat/in-vitro property; the same study flags potent LH suppression and a narrow therapeutic index. It is preclinical and never approved, its drug class is FDA-flagged for liver injury and testosterone suppression, and it is prohibited in sport.
• "If it's labeled BMS-564929, that's what's in it." Not reliably. In the JAMA 2017 analysis, only about half of products sold as SARMs contained the labeled compound; many contained a different drug or nothing active.

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This entry is educational and summarizes published research and public regulatory information. It is not medical advice, a recommendation, or a guide to obtaining or using any substance. Not legal advice — check your own jurisdiction. Last reviewed 2026-07-10.