Performance & GH axis
YK-11
YK11
YK-11 is a synthetic steroid marketed as a SARM, though it is structurally a steroid and mechanistically distinct from the non-steroidal SARMs. It has never been in human clinical trials and is not approved anywhere.
Also known as: YK 11
- Status
- YK-11 is a research compound and not approved by the FDA for human use.
- Evidence
- Preclinical. Evidence comes from animal or lab studies; effects in people are not established.
- Half-life
- Not established — no human pharmacokinetic data exist.
- How it's taken
- Oral, in non-clinical use
- Mechanism
- Anabolic (IGF-1 / myostatin)
- Pathways
- Androgen, Myostatin
How YK-11 works
YK-11 has a steroidal backbone derived from dihydrotestosterone with a gem-dimethyl ester group. Cell-culture work indicates it acts as a partial androgen receptor agonist and additionally induces follistatin expression, which would inhibit myostatin — the basis of claims that it combines two anabolic mechanisms. This has been shown in cultured myoblasts, not in animals or people.
What research has looked at
- Cell-culture studies do show follistatin induction and myoblast differentiation, so the proposed dual mechanism has some in vitro basis.
- It is orally active.
- Its steroidal structure is unusual among compounds marketed as SARMs, which makes it pharmacologically distinct from ostarine, RAD-140 and LGD-4033 despite being sold alongside them.
Evidence level: Preclinical. Evidence comes from animal or lab studies; effects in people are not established. These are areas studied or reported, not promised effects.
Reported side effects and risks
- There are no animal efficacy studies and no human trials of any kind. The entire case for YK-11 rests on cell-culture experiments, which is a weaker evidence base than any other compound marketed in this category. No regulator has approved it, the human evidence base is limited, and material sold under this name is research chemical supply with unverified identity, purity, sterility and dose accuracy.
- Because it is a steroid rather than a non-steroidal SARM, hepatotoxicity concerns associated with 17-alpha-alkylated oral steroids are frequently raised, though it has not been formally characterised.
- Testosterone suppression is expected from androgen receptor agonism but has not been quantified in humans.
- The FDA has warned about SARM-marketed products generally, citing liver injury and cardiovascular risk.
- Prohibited at all times under the WADA Prohibited List.
Sources
- PubMed research on YK-11 follistatin myoblast steroid SARM · NIH · National Library of Medicine
- DrugBank record for YK-11 · DrugBank
- Active clinical trials for YK-11 · U.S. National Library of Medicine
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YK-11 FAQ
What is YK-11?
YK-11 is a synthetic steroid marketed as a SARM, though it is structurally a steroid and mechanistically distinct from the non-steroidal SARMs. It has never been in human clinical trials and is not approved anywhere.
How does YK-11 work?
YK-11 has a steroidal backbone derived from dihydrotestosterone with a gem-dimethyl ester group. Cell-culture work indicates it acts as a partial androgen receptor agonist and additionally induces follistatin expression, which would inhibit myostatin — the basis of claims that it combines two anabolic mechanisms. This has been shown in cultured myoblasts, not in animals or people.
Is YK-11 FDA approved?
No. YK-11 is a research compound and not approved by the FDA for human use. Evidence level: preclinical. Evidence comes from animal or lab studies; effects in people are not established.
How is YK-11 taken?
Oral, in non-clinical use.
What side effects have been reported with YK-11?
Reported in the sources: There are no animal efficacy studies and no human trials of any kind. The entire case for YK-11 rests on cell-culture experiments, which is a weaker evidence base than any other compound marketed in this category. No regulator has approved it, the human evidence base is limited, and material sold under this name is research chemical supply with unverified identity, purity, sterility and dose accuracy; Because it is a steroid rather than a non-steroidal SARM, hepatotoxicity concerns associated with 17-alpha-alkylated oral steroids are frequently raised, though it has not been formally characterised; Testosterone suppression is expected from androgen receptor agonism but has not been quantified in humans; The FDA has warned about SARM-marketed products generally, citing liver injury and cardiovascular risk; Prohibited at all times under the WADA Prohibited List.
Educational summary compiled from the sources listed above. Not medical advice. Peptide Vault does not sell, source or recommend any compound. Talk to a qualified clinician before starting or changing anything.