PepVault
/ database / Myostatin Inhibitor

Follistatin 344

Also: FST

Pre-clinical myostatin inhibitor — outsized muscle growth in animal models.

Evidence
anecdotal
Legal status
research only
Half-life
~unclear in humans
Routes
subq · im
View on Limitless LifeAdd to compare
What it is

Follistatin is the body's natural myostatin antagonist. Recombinant FST-344 produces dramatic muscle hypertrophy in animals and is heavily discussed in research-peptide circles despite very limited human data.

Mechanism

Binds and neutralizes myostatin and activin, releasing the brake on muscle growth.

Outcomes it's matched to
Safety

Unknown long-term safety; theoretical concerns around uncontrolled growth.

  • Active malignancy
  • Pregnancy
  • Anyone without medical supervision
Legal context

Research use only. No human safety data.

1:1 GUIDANCE

Have questions about this peptide?

Get free 1:1 guidance from a peptide professional before you start. They'll help you think through dosing, stacking, and whether this fits your goals.

REQUEST A CALL →
PepVault

An outcome-driven reference for modern peptides. Educational only — not medical advice, not a sales platform, not affiliated with any clinic.

Disclaimer: PepVault is an educational resource. Nothing on this site is medical advice. Many peptides discussed are research compounds and are not approved by the FDA or equivalent agencies. Always consult a qualified clinician before starting any protocol.

© 2026 PepVault