YK11 – Myostine

What is YK-11?

YK-11 is a synthetic myostatin inhibitor often categorized as a SARM, though structurally it more closely resembles a steroidal compound. It was originally developed for its ability to promote muscle growth through selective activation of androgen receptors and suppression of myostatin—a protein that limits muscle development.

In research settings, YK-11 is known for its dual anabolic pathways: it enhances muscle growth via androgen receptor activation while simultaneously freeing the body from myostatin’s growth-limiting effects. This unique action has made it one of the most powerful and aggressive compounds studied in the SARMs category for building lean mass and strength.

Chemical Properties

How Does YK-11 Work?

YK-11 works by selectively binding to androgen receptors in muscle tissue while inhibiting myostatin. Myostatin is a protein that regulates muscle growth by preventing excessive hypertrophy. By blocking myostatin and enhancing follistatin expression, YK-11 may dramatically increase lean muscle mass in research subjects.

Its steroidal structure differentiates it from other SARMs and results in a more intense anabolic response—comparable in strength to moderate anabolic steroids, yet with a tissue-targeted focus. Because of this, YK-11 is often used in short, high-impact research cycles.

Potential Benefits Of YK-11

• Extreme Muscle Growth: May lead to rapid hypertrophy via myostatin inhibition and androgen activation.
• Strength Increase: Rapid force output gains observed in performance-based models.
• Fat Loss Support: Improved lean-to-fat ratio due to heightened metabolic demand.
• Bone Density: Preliminary research suggests potential bone-building properties.

Clinical Research & Findings

Research on YK-11 remains limited compared to other SARMs, but early data and anecdotal reports highlight its immense anabolic potential. Studies have observed significantly upregulated follistatin production and suppression of myostatin expression—markers correlated with increased muscle size. Because of its potent profile, YK-11 is often reserved for short-term, high-intensity research cycles, with careful observation of side effect markers such as testosterone suppression and liver enzyme changes.

YK-11 Dosage Guide

YK-11 is a powerful compound best used in moderate dosages. The recommended research dose ranges from 5–15mg per day. Due to its short half-life, split dosing (morning and evening) is advised in protocols to maintain stable serum levels. Research cycles typically last 6–8 weeks due to its strong androgenic effects and steroidal structure.

YK-11 is known to suppress natural testosterone production, so a full post-cycle therapy (PCT) protocol is recommended following use. It’s also advisable to monitor liver function throughout the cycle.

Here’s a quick breakdown by goal:

• Muscle Mass & Strength Gains:
  10–15mg per day for 6–8 weeks

• Recomp or Cutting Cycle:
  5–10mg per day for 6 weeks

• Strength Focused Research:
  10mg per day for 4–6 weeks

Stacking YK-11 With Other SARMs

“Can YK-11 be stacked?” Yes, but with caution. YK-11 is extremely potent and should only be stacked with non-methylated SARMs in short cycles. It is often combined in high-impact bulking or strength protocols.

Here are three strategic stack options:

1. RAD-140 (Testolone): Enhances muscle growth and strength while complementing YK-11’s myostatin suppression.
2. Ibutamoren (MK-677): Supports recovery and GH levels to mitigate potential stress on the system during YK-11 cycles.
3. Ostarine (MK-2866): Adds joint and muscle preservation benefits to offset YK-11’s intense anabolic load.

FAQs

Is YK-11 legal?

Yes. YK-11 is legal for research use in Canada and most countries. It is not classified as a controlled substance but is not approved by the FDA for human consumption.

Does YK-11 suppress testosterone?

Yes. YK-11 is known to suppress natural testosterone production and should be followed by a full post-cycle therapy (PCT).

How long is the half-life of YK-11?

Estimates suggest a short half-life of 6–10 hours, which is why split dosing is recommended in most research protocols.

What form does this product come in?

This product is available in powder and liquid form with ≥98% purity, suitable for validated laboratory research applications.

Disclaimer

For laboratory use only. Not for human or veterinary use.

This material is intended strictly for research purposes under controlled laboratory conditions. It is the buyer’s responsibility to ensure legal and ethical use in accordance with institutional, local, and federal guidelines.

Always wear proper safety equipment and follow appropriate handling procedures.