YK-11
YK-11
Also known as: YK11, YK-11 Myostatin Inhibitor
Overview
Key Facts
Primary Goal: Research and therapeutic applications of YK-11
Partial agonist at the androgen receptor, inducing selective gene transcription in muscle tissue. Increases expression of follistatin in C2C12 myoblasts, indirectly inhibiting myostatin.
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Compare YK-11 prices →Dosing Information
6-10 hours (estimated, limited pharmacokinetic data)
5–15 mg
Once daily (oral or injectable, split AM/PM by some researchers)
6-8 weeks (with post-cycle therapy consideration)
Benefits
- Dual mechanism: androgen receptor activation plus myostatin inhibition via follistatin
- May promote muscle growth exceeding traditional SARMs
- Selective anabolic effects with potentially reduced androgenic side effects
- Increases follistatin expression in myocytes
- Oral bioavailability eliminates need for injections in some formulations
Side Effects
Mechanism of Action
Partial agonist at the androgen receptor, inducing selective gene transcription in muscle tissue
Increases expression of follistatin in C2C12 myoblasts, indirectly inhibiting myostatin
Steroidal backbone (19-nor DHT derivative) provides androgen receptor binding affinity
Does not appear to induce full AR conformational change, leading to gene-selective effects
Downstream Akt phosphorylation promotes anabolic signaling in skeletal muscle
Contraindications
Do not use this peptide if any of the following apply:
- Pre-existing liver disease or elevated liver enzymes
- Women of childbearing potential (steroidal compound)
- Adolescents or those with open growth plates
- History of hormone-sensitive cancers
- Concurrent use of hepatotoxic medications
Storage & Reconstitution
Unreconstituted (Powder)
Reconstituted (Mixed)
For suppliers & labs
Building a YK-11 catalogue? Custom waterproof vial & pen labels (zero MOQ, UK print) on PepPrint →
Research Summary
YK-11 was first described by Kanno et al. (2011) in a study on C2C12 myoblast cells, demonstrating that it induced myogenic differentiation and increased follistatin expression more effectively than DHT. Subsequent in vitro studies confirmed its dual AR-agonist and myostatin-inhibiting activity. No in vivo animal or human clinical trials have been published. Its classification remains debated — it shares features with both SARMs and anabolic steroids. Extreme caution is warranted due to the complete absence of clinical safety data.
Frequently Asked Questions
Common questions about YK-11
UK-Specific Information
Exclusive data points and guidance for UK residents using YK-11
UK Lab Testing
UK Lab Testing
Recommended labs: Medichecks, Thriva (£89-£149 for peptide safety panel)
Why this matters: UK-specific lab testing guidance not available on US competitor sites
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Note: Peptide stacking should only be done under the guidance of a qualified healthcare professional. Individual responses may vary.
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