PROTOKOLwiki
COMPOUNDS / SARM / YK-11
SARM

YK-11

HIGH RISK
BEST FOR:Muscle Growth●●●●●●○○○○6/10
YK-11 · YK11 · YK 11 · (17Α,20E)-17,20-[(1-METHOXYETHYLIDENE)BIS(OXY)]-3-OXO-19-NORPREGNA-4,20-DIENE-21-CARBOXYLIC ACID METHYL ESTER
SARMSteroidalAndrogen ReceptorMyostatin InhibitorWADA BannedMuscle Building

Steroidal SARM and partial androgen receptor agonist with myostatin-inhibiting properties, sold as a grey-market muscle-building supplement.

ROUTE / DOSAGE
LOW2mg
STANDARD5-10mg
HIGH15mg+
Note: Split into 1-2 daily doses; compound is chemically unstable and hydrolyzes rapidly
CYCLE
4-8 weeks followed by PCT
BIOAVAILABILITY
low oral (~15-30% estimated)
ACTIVE DURATION
12-24h (subjective)
STORAGE
Room temperature dry away from light and moisture compound is chemically unstable and hydrolyzes rapidly in solution
HALF-LIFE
6-10h (plasma)
DURATION BREAKDOWN
Total12-24h per dose
Onset1-2h
Come up1-3 weeks (noticeable effects)
Peak3-4 weeks (cycle midpoint)
Offset1-2 weeks (washout)
After effects2-4 weeks (testosterone suppression)
Duration varies by route, dose, and individual. Source: community reports.
§ 01 — EFFECTS
6 documented
Increased muscle mass
Enhanced strength
Improved bone density
Myostatin inhibition
Mild androgenic effects
Testosterone suppression at higher doses
§ 02 — RISKS
Testosterone suppression and HPTA disruption
Liver toxicity (hepatotoxicity risk)
Lipid profile deterioration (reduced HDL)
No human clinical safety data
Chemical instability and unknown degradation products
WADA-prohibited substance — doping violation
§ 03 — INTERACTIONS
Interaction data not yet available for this compound.
§ 04 — SCIENCE

YK-11 has been characterized primarily in doping control and analytical chemistry literature, with no published human clinical trials. In vitro studies suggest it acts as a partial androgen receptor agonist and may inhibit myostatin, a protein that limits muscle growth. The compound is chemically unstable, readily hydrolyzing within hours, which complicates detection and may affect bioavailability. It has been detected in dietary supplements sold online, sometimes without disclosure on product labels. WADA has prohibited SARMs including YK-11 since 2008, and it has been identified in human doping control samples.

§ 06 — SOURCES
[1]
Detection of selective androgen receptor modulator YK-11 in a doping control sample
pubmed.ncbi.nlm.nih.gov ↗
[2]
Equine metabolism of the selective androgen receptor modulator YK-11 in urine and plasma following oral administration
pubmed.ncbi.nlm.nih.gov ↗
[3]
Mass spectrometric characterization of the selective androgen receptor modulator (SARM) YK-11 for doping control purposes
pubmed.ncbi.nlm.nih.gov ↗
[4]
Detection of SARMs in doping control analysis
pubmed.ncbi.nlm.nih.gov ↗
[5]
Detection of nonsteroidal and steroidal selective androgen receptor modulators in equine hair after oral administrations
pubmed.ncbi.nlm.nih.gov ↗
[6]
Development and validation of LC-MS/MS method for screening six SARMs in dietary supplements
pubmed.ncbi.nlm.nih.gov ↗
Disclaimer. Protokol.wiki is an informational reference. Nothing on this site is medical advice. Compounds listed may be unapproved, unregulated, or illegal in your jurisdiction. Consult a licensed physician before use. Data compiled from peer-reviewed literature.
METHODOLOGYCONTRIBUTECONTACT