Supplement Scholar
Anabolic / Growth Factor

Follistatin-344

Research compound. This is not a dietary supplement. Unless it is identified as an approved prescription drug, it is not approved by the FDA for human use. This page summarizes published research for education only; we do not sell it or link to sellers.

Follistatin-344. Natural myostatin-binding protein that releases the brake on muscle hypertrophy.

How it works. Sequesters myostatin and activin in circulation, removing inhibitory tone on muscle growth and influencing FSH dynamics.

What the research supports. 2 graded claims. Strongest: Theoretical hypertrophy support (preclinical).

Hormonal impact. Effects on Myostatin (free), Activin A, FSH.

Side effects and interactions. 0 medication interactions listed. Serious: Off-target effects on reproductive and hepatic activin signaling.

Stacking. Pairs well with Progressive resistance training. Avoid combining with Reproductive or hormonal disorders.

Common forms. Available as Subcutaneous or intramuscular injection (research).

Community. Experiences from people who have tried Follistatin-344. Anecdotes are not medical advice.

Follistatin-344. Natural myostatin-binding protein that releases the brake on muscle hypertrophy.

No single structure

What it is

Follistatin-344 is an isoform of follistatin, a glycoprotein that binds and inactivates myostatin (GDF-8) and activin A, both of which limit muscle growth.

How it works

Sequesters myostatin and activin in circulation, removing inhibitory tone on muscle growth and influencing FSH dynamics.

Pathways

  • Myostatin (GDF-8) neutralization
  • Activin A sequestration

Effects

  • ⊘Myostatin signaling inhibits
  • +Muscle hypertrophy capacity supports

What the research supports

Theoretical hypertrophy supportpreclinical
Studied in muscular-dystrophy researchpreclinical

Strong: consistent results across large trials or meta-analyses. Moderate: several trials, mostly positive. Limited: small or mixed studies. Preclinical: animal or cell research only.

Hormonal impact

↓Myostatin (free)decreases
↓Activin Adecreases
~FSHmodulates

Side effects & interactions

Common side effects

  • Injection-site soreness

Serious

  • Off-target effects on reproductive and hepatic activin signaling

No notable medication interactions listed.

Check any supplement–medication combination with your pharmacist before starting.

Combines with

Pairs well

  • Progressive resistance trainingRemoving the brake matters only if a growth signal is present.

Avoid combining

  • Reproductive or hormonal disordersActivin axis disruption is poorly characterized.

Common forms

  • Subcutaneous or intramuscular injection (research)

Discussion

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