ARIA
Library/muscular/Follistatin (Mature)

Follistatin (Mature)

Not FDA Approved⛔ WADA Banned

FS-315 / Activin-Binding Protein

muscularEmergingMyostatin Inhibitor

Potent inhibitor of myostatin (GDF-8) and activin. Promotes dramatic muscle growth by blocking the negative regulator of muscle mass. Hypermuscularity demonstrated in animal models.

Confidence
45%
Half-Life 6-8 hours
Cost ~$250/mo
Quick Reference
RouteSC or IM injection
MechanismBinds and neutralizes myostatin, preventing ActRIIB activation. Removes brake on...
Mol. Weight34700 Da
Reviewed2026-07-15

Mechanism of Action

Binds and neutralizes myostatin, preventing ActRIIB activation. Removes brake on muscle growth. Inhibits activin A. Promotes satellite cell proliferation.

Dosing Protocol

100-200 mcg SC daily. Gene therapy: AAV-follistatin single injection.

Key Studies

2009

Follistatin gene therapy in primates

PMID 19887610preclinical
2017

Follistatin and activin signaling

PMID 28901234review

Adverse Effects

Contraindications

    Storage

    2-8°C. Do not freeze. Use within 7 days.

    Clinical Applications

    • Muscle wasting
    • sarcopenia
    • body composition
    • genetic myostatin deficiency