Follistatin 344

also known as: FST-344, Fst344

MetabolicGH SecretagogueadvancedSubQIntramuscular

Half-life: ~3–6 hours

About

Follistatin 344 is a naturally occurring glycoprotein that acts as a potent inhibitor of myostatin and activin — key negative regulators of muscle growth. The "344" refers to the 344-amino acid isoform that circulates in the bloodstream. It produces dramatic lean mass increases and fat loss.

Mechanism of Action

Binds and neutralizes myostatin, activin A, activin B, and GDF-11, preventing these TGF-β family members from inhibiting muscle protein synthesis. Also reduces FSH (follicle-stimulating hormone) secretion via activin binding.

Primary Benefits

Dramatic muscle mass gains
Myostatin inhibition
Increased strength
Fat loss
Enhanced athletic performance

Side Effects & Considerations

Potential tendon strain from rapid muscle growth (connective tissue may lag)
FSH suppression (may affect fertility)
Joint discomfort
Potential tumor promotion risk (theoretical)
Very limited human safety data

Research Notes

Gene therapy using Follistatin has shown dramatic muscle gains in Becker MD patients. Rodent studies show 2x muscle mass increase. Human injection research is primarily from the bodybuilding community.

Stacking Guide

Synergistic Stacks

IGF-LR3

IGF-LR3 adds direct muscle protein synthesis downstream; Follistatin 344 removes the myostatin brake — powerful combination.

PEG MGF

PEG-MGF drives satellite cell activation in muscles; Follistatin 344 removes inhibitory signals — highly synergistic for hypertrophy.

Redundant / Avoid Together

ACE-031

Both work by blocking myostatin/activin pathways — combining significantly increases side effect risk.

Complementary Cycles

BPC-157

Use BPC-157 during and after Follistatin cycles to protect tendons and connective tissue from rapid muscle growth stress.

TB-500

TB-500 provides connective tissue support to keep pace with rapid muscle growth from Follistatin.

Storage & Reconstitution

Storage

Refrigerate at 2–8°C (36–46°F). Do not freeze.

Reconstitution

Reconstitute with bacteriostatic water. Handle gently.

Goals Addressed

Muscle Gain

Quick Stats

Half-Life: ~3–6 hours
Admin Routes: SubQ, Intramuscular
Experience Level: advanced

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