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COMPOUNDS / SARM / OSTARINE
SARM

OSTARINE

MEDIUM RISK
BEST FOR:Recomposition●●●●●●●○○○7/10
OSTARINE · ENOBOSARM · GTX-024 · GTX-024 · MK-2866 · S-22 · OSTARINE · MK2866
SARMAnabolicBodybuildingAndrogen ReceptorWADA BannedResearch Chemical

Non-steroidal selective androgen receptor modulator developed for muscle wasting, widely used off-label for body recomposition.

ROUTE / DOSAGE
LOW10mg
STANDARD20-25mg
HIGH50mg+
Note: Daily dosing; effects accumulate over weeks. Split dose optional due to long half-life.
CYCLE
8-12 weeks followed by 4-week PCT
BIOAVAILABILITY
~60% oral
ACTIVE DURATION
24h (subjective)
STORAGE
Room temperature dry away from light store in sealed container
HALF-LIFE
~24h (plasma)
DURATION BREAKDOWN
Total4-8 weeks (cycle-dependent)
Onset2-4h (plasma), days for effects
Come up1-2 weeks
PeakWeeks 4-8 of cycle
Offset1-2 weeks after discontinuation
After effects2-4 weeks (suppression recovery)
Duration varies by route, dose, and individual. Source: community reports.
§ 01 — EFFECTS
6 documented
Increased lean muscle mass
Improved muscle vascularization
Enhanced muscle cell differentiation
Reduced body fat (mild)
Increased capillary density in muscle
Testosterone suppression at higher doses
§ 02 — RISKS
Cardiotoxicity including fibrosis markers and cardiomyopathy marker elevation, more pronounced in males
Dose-dependent testosterone suppression requiring post-cycle therapy
Uterotrophic effects at higher dosages indicating off-target androgenic activity
Increased myostatin gene expression may counteract anabolic effects
Decreased submaximal endurance capacity
WADA-prohibited substance; detection in urine and oral fluid can persist for weeks
§ 03 — INTERACTIONS
Interaction data not yet available for this compound.
§ 04 — SCIENCE

Multiple preclinical studies in rats demonstrate that ostarine increases muscle mass, capillary density, and myogenic differentiation markers (myogenin, MyoD, MyH) via androgen receptor activation. A 2023 study found ostarine increased myostatin gene expression and paradoxically decreased submaximal endurance without affecting maximal time to exhaustion. Cardiotoxicity has been documented in vitro, with increased fibrosis markers (αSMA, fibronectin) in male cardiac fibroblasts and elevated cardiomyopathy marker βMhc in rat hearts, particularly at high doses. Ostarine showed no additive metabolic benefits when combined with exercise in obese rats. Human clinical trials for cancer cachexia and muscle wasting were conducted but the compound was never approved by any regulatory agency. Evidence for efficacy and safety in humans remains limited to early-phase trials, and long-term risks are poorly characterized.

§ 06 — SOURCES
[1]
PubMed PMID 34445197
pubmed.ncbi.nlm.nih.gov ↗
[2]
PubMed PMID 38451281
pubmed.ncbi.nlm.nih.gov ↗
[3]
PubMed PMID 35457222
pubmed.ncbi.nlm.nih.gov ↗
[4]
PubMed PMID 37543162
pubmed.ncbi.nlm.nih.gov ↗
[5]
PubMed PMID 34480092
pubmed.ncbi.nlm.nih.gov ↗
[6]
PubMed PMID 37865959
pubmed.ncbi.nlm.nih.gov ↗
[7]
PubMed PMID 33042018
pubmed.ncbi.nlm.nih.gov ↗
[8]
PubMed PMID 38499138
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.
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