Follistatin
fol-ih-STAT-in
A protein that blocks myostatin — the molecule that limits muscle growth — potentially allowing greater muscle development.
Also known as: FST, Follistatin 344
Last reviewed: April 2026
What It Does
Your body produces myostatin to limit muscle growth. Follistatin binds to and neutralizes myostatin, removing this natural brake on muscle development. In animal studies, follistatin overexpression leads to dramatic muscle hypertrophy.
Why People Take It
How It's Administered
Subcutaneous Injection
Injection
Frequency
Daily for short cycles
Pain Level
●○○ Minimal
Self-Administered
Yes — at home
Typical Range
100mcg – 200mcg
What To Expect
Month 1–2
Potential strength improvements alongside training.
Month 3+
Possible body composition changes. Very variable.
Side Effects
Overall: Mild
Uncommon (0.1–1%)
Limited data
Human side effect profile not well characterized.
Who Should NOT Take This
• Pregnancy
• Very limited human data
• Cardiovascular disease (theoretical concern with uncontrolled muscle growth)
Drug Interactions
• Insufficient data
Pregnancy: Not studied. Avoid.
Clinical Details
Compare With Similar Peptides
Follistatin targets muscle growth specifically via myostatin. TB-500 targets tissue repair broadly. Different goals despite both being in the 'muscle' category.
Open Full Comparison Tool →Frequently Asked Questions
This compound is in early research stages. We do not currently offer it.
Looking for something similar? See what we offer for Muscle & Recovery.
This compound is in early research stages. It has not been FDA-approved and may not be available through compounding pharmacies. The information below is for educational purposes only. Do not attempt to self-administer research compounds.