AC-262,536 for Selective Androgen Modulation — SARMs
66% anabolic/27% androgenic efficacy of testosterone in preclinical models. Acadia Pharmaceuticals. Very limited data. No human studies. NOT FDA-approved.
Overview
AC-262,536 is a non-steroidal selective androgen receptor modulator developed by Acadia Pharmaceuticals as a companion compound to ACP-105 in their AR research program. In preclinical studies using the Hershberger bioassay in castrated rats, AC-262,536 demonstrated approximately 66% of the anabolic efficacy of testosterone (as measured by levator ani muscle weight increase) while exhibiting only 27% of the androgenic activity (as measured by prostate weight stimulation). This anabolic-to-androgenic ratio of approximately 2.45:1 suggests moderate tissue selectivity, positioning AC-262,536 as a compound with meaningful anabolic potential and significantly reduced androgenic side effects relative to testosterone. The compound was characterized primarily in Acadia Pharmaceuticals patent applications and a limited number of peer-reviewed publications. AC-262,536 acts as a partial androgen receptor agonist with selectivity driven by differential coactivator recruitment in androgen-responsive tissues. Despite the promising selectivity profile, Acadia Pharmaceuticals did not advance AC-262,536 into clinical development, and no human pharmacokinetic, safety, or efficacy data exist. The compound has never been evaluated in an IND-enabling study, and its drug-like properties (oral bioavailability, metabolic stability, off-target binding) remain incompletely characterized. AC-262,536 represents one of the least-studied compounds available on the gray market, with virtually all human usage information derived from anecdotal reports. It is NOT FDA-approved, has no regulatory status, and is prohibited by WADA.
Indications
- Preclinical research into selective androgen receptor modulation
- Basic research compound for AR tissue-selectivity studies
- Investigation of partial AR agonism and anabolic/androgenic dissociation
- Theoretical potential for sarcopenia and osteoporosis (preclinical rationale only)
- No clinical investigations conducted or planned
Mechanism of Action
AC-262,536 is taken orally. No published pharmacokinetic data exist for any species. Bioavailability, half-life, Tmax, and metabolic pathways remain uncharacterized. Dosing frequency is entirely speculative
Dosing
| Compound | Dose | Frequency | Notes |
|---|---|---|---|
| AC-262,536 | 10 mg/day | Once daily (speculative) | Low dose; no scientific basis for any specific dosing protocol |
| AC-262,536 | 20 mg/day | Once daily (speculative) | Moderate dose commonly reported in anecdotal forums |
| AC-262,536 | 30 mg/day | Once daily (speculative) | Higher dose; entirely unknown risk profile at this level |
Evidence Grade
GRADE D
Safety & Contraindications
- NOT FDA-approved — no human studies conducted
- Extremely limited published data — primarily patent filings
- Unknown human pharmacokinetics — all dosing is speculative
- 66% anabolic efficacy suggests moderate but not maximal potency
- 27% androgenic activity suggests reduced but not eliminated androgenic risk
- No safety data in any species beyond rodent Hershberger assay
- WADA prohibited substance
- Gray-market only — severe quality concerns
- Unknown hepatotoxicity, cardiotoxicity, and long-term safety
- No drug interaction data available