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Follistatin / Myostatin inhibitors (ACE-031, YK-11)

Evidence: ★★☆☆☆ · Status: Not Approved

💡 Did you know? Some cattle — and a few unusually strong children — are born muscular because they lack myostatin, the natural 'brake' on muscle growth.

In plain English

Your body caps muscle growth with a protein called myostatin. These release that cap — the same reason certain super-muscular cattle and dogs exist. Human safety is unknown; ACE-031 trials were stopped for side effects (nosebleeds, vessel changes).

How it works

Block myostatin (MSTN/GDF-8) — the body's natural brake on muscle size. Removing the brake (as in "double-muscled" animals and rare human mutations) permits large muscle growth.

Molecular target & official sources

MSTN myostatin/GDF8 (NCBI Gene) · Follistatin FST (NCBI Gene)

Watch out

Off-target vascular/bleeding effects; unknown long-term safety.

Bottom line

Compelling mechanism, unproven and risky in humans.

Helps with: Build Muscle & Strength · Hormones & Testosterone

Availability & where to buy

Not widely approved. Not approved for general sale in most markets (Singapore included). Grey-market only — dose, purity and legality uncertain.

Common questions

Does Follistatin / Myostatin inhibitors (ACE-031, YK-11) actually work?

Human-evidence rating: 2 of 5. Compelling mechanism, unproven and risky in humans.

What are the risks or side effects of Follistatin / Myostatin inhibitors (ACE-031, YK-11)?

Off-target vascular/bleeding effects; unknown long-term safety.

Is Follistatin / Myostatin inhibitors (ACE-031, YK-11) legal or approved?

Regulatory status: Not Approved.