YK-11 (Myostine) Capsules

Brief Intro

YK-11 (Myostine) Capsules contain a synthetic steroidal selective androgen receptor modulator (SARM) structurally derived from dihydrotestosterone (DHT). Unlike most non-steroidal SARMs, YK-11 functions as a partial agonist of the androgen receptor and uniquely induces strong expression of follistatin, a potent myostatin inhibitor. By inhibiting myostatin, YK-11 promotes significant muscle hypertrophy and bone growth beyond typical SARMs. It has demonstrated potent anabolic effects in preclinical studies, including enhanced muscle cell differentiation and protection against muscle wasting. These capsules are intended strictly for scientific research and analytical purposes and are not for human consumption.

Chemical Structure / Physical Properties

• Chemical Name: 17α-methyl-δ2-17β-hydroxyestra-4,9-dien-3-one

• Molecular Formula: C25H34O6

• Molecular Weight: 430.54 g/mol

• CAS Number: 1370003-76-1

• Purity: Typically ≥98%

• Form: White to pale yellow crystalline powder encapsulated in capsules

• Melting Point: 134–137 °C

• Solubility: Slightly soluble in chloroform and methanol

• Storage: Store at -20°C in a dry, dark environment

Pharmacology and Mechanism of Action

YK-11 acts as a partial androgen receptor agonist that does not induce the full receptor activation typical of natural androgens but significantly upregulates follistatin expression. Follistatin inhibits myostatin, a negative regulator of muscle growth, thereby promoting muscle hypertrophy and increased bone density. In vitro studies show YK-11 enhances myogenic regulatory factors (MyoD, Myf5, myogenin) more potently than dihydrotestosterone (DHT), leading to increased muscle cell differentiation and growth. Animal studies suggest YK-11 may protect against muscle wasting and reduce inflammation.

Intended Use

YK-11 Capsules are intended strictly for laboratory research, including pharmacological, biochemical, and toxicological studies on selective androgen receptor modulation, muscle growth, myostatin inhibition, and bone health. They are not for human consumption or clinical use.

Packaging & Shipping

Capsules are securely packaged and shipped discreetly with tracking. Typical delivery times range from 24 to 72 hours within the USA and up to 5 days internationally, depending on destination. Shipping fees are calculated at checkout based on location.

Legal & Compliance Disclaimer

All products are sold for research purposes only and are not intended for human consumption. Customers must verify the legal status of YK-11 in their jurisdiction before ordering. The vendor reserves the right to accept or decline orders based on intended use.

Dosage and use

Next lvl muscle YK-11 mutant is effective at both high and low doses. Beginners should start with a dose of 5mg per day. More experienced users can take 10 to 15mg. The half-life of myostin is 6 to 10 hours, making it advisable to split the daily intake in half. Use myostin in a cycle of 4 to 8 weeks followed by a Post Cycle Therapy (PCT).

Myostine can be used during cutting and bulking and can be combined with other agents.

 What are SARMs?

SARMs are Selective Androgen Receptor Modulators. Put simply, these substances can tell your cells that they need to, for example, create more muscle mass or break down more fat. Each SARM has a different effect, allowing you to achieve very targeted aesthetic and physical goals. And that without experiencing unpleasant side effects such as hair loss, acne and liver damage.

Note: All information about these research chemicals and the research chemicals themselves are for educational and research purposes only. These products are not a supplement and are not suitable for human consumption.