Follistatin 344
Also known as: FST-344 · Follistatin · Myostatin Inhibitor
A naturally occurring glycoprotein that inhibits myostatin and activin, removing the genetic brake on muscle growth and enabling enhanced muscle development.
Overview
Follistatin 344 is a naturally occurring glycoprotein that acts as a potent inhibitor of myostatin, activin, and other members of the TGF-beta superfamily. Myostatin is the body's primary negative regulator of muscle growth — it acts as a genetic brake that limits how much muscle tissue can develop. By binding to and neutralizing myostatin, Follistatin effectively removes this brake, allowing for enhanced muscle hypertrophy and potentially hyperplasia. Animals with naturally elevated follistatin levels or myostatin deficiency develop dramatically increased muscle mass.
Follistatin 344 is the full-length isoform that is processed into the active FST-315 and FST-288 forms. In research, it has shown remarkable ability to increase lean muscle mass, improve strength, and enhance body composition. It is also being studied for its potential in treating muscular dystrophy and age-related sarcopenia.
Mechanism of Action
Binds to myostatin, activin A, and other TGF-beta ligands with high affinity, preventing them from activating their receptors (ActRIIB). This removes the negative regulation of muscle growth, allowing increased satellite cell activation, protein synthesis, and muscle fiber hypertrophy. Also modulates follicle-stimulating hormone (FSH) through activin inhibition.
Key Benefits
Potential Side Effects
Common Stacks
This peptide is commonly combined with the following compounds for synergistic effects:
Known Interactions
The following interactions have been documented for Follistatin 344. Always consult a healthcare professional before combining compounds.
Synergistic (1)
Both inhibit myostatin through different mechanisms. Follistatin binds and neutralizes myostatin directly while YK-11 increases follistatin production. Powerful muscle growth stack.
Scientific References
Quick Reference
Typical Dose
100mcg-300mcg
Frequency
1x daily pre/post workout
Route
Subcutaneous injection
Half-Life
~6-8 hours
Cycle Length
10-30 days; daily use, followed by 8-12 weeks recovery
FDA Status
Research compound — not FDA approved. Being studied for muscular dystrophy and sarcopenia.
Need to calculate dosing?
Use our reconstitution calculator to determine exact syringe measurements.
Open CalculatorThis information is for educational purposes only. Consult a qualified healthcare professional before using any peptide. Dosing information reflects commonly reported protocols and may not be appropriate for everyone.
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