Follistatin-344

FST-344 · Follistatin

Growth HormoneNot ApprovedPhase IResearchSubQ

Popular for:Myostatin inhibition, muscle growth, muscular dystrophy research

1

Registered Trials

0

Trial Publications

5

PubMed References

Phase I

Evidence Level

Overview

Follistatin-344 is a synthetic version of the naturally occurring follistatin protein, which functions as an inhibitor of myostatin and activin signaling. The short version: people usually care about it for myostatin inhibition, muscle growth, muscular dystrophy research, but the strength of the evidence depends heavily on indication and study type.

Follistatin-344 is a synthetic version of the naturally occurring follistatin protein, which functions as an inhibitor of myostatin and activin signaling. Myostatin is a negative regulator of muscle growth — by binding and neutralizing myostatin, follistatin effectively removes the body's natural brake on muscle development.

Follistatin gained public attention through gene therapy experiments where mice treated with follistatin gene therapy developed dramatically increased muscle mass. The synthetic injectable form (Follistatin-344 and the related Follistatin-315) allows researchers to study myostatin inhibition without gene therapy approaches.

Research Snapshot

What the evidence says

Phase I

Follistatin-344 currently shows 1 registered trials from ClinicalTrials.gov, 0 PubMed trial publications (0 RCT-tagged), and 5 PubMed references matching the stored source query. Treat PubMed references as literature surface area, not a count of clinical trials.

Known vs uncertain

Known signals

  • 1 registered trials are tracked from ClinicalTrials.gov intervention records.
  • 0 PubMed clinical-trial publications are indexed.
  • 0 PubMed randomized controlled trial publications are indexed.
  • 5 PubMed references are tracked separately from trial counts and can include animal, in-vitro, review, mechanism, or clinical records.

Open questions

  • Evidence strength may vary by indication, route, formulation, and population.
  • Public anecdotes can highlight interest or concern but do not establish clinical efficacy.
  • Regulatory status and compounding access can change independently from the research literature.

Mechanism of Action

Follistatin-344 binds directly to myostatin and activin A, preventing them from interacting with their receptors (ActRIIB).

Key Research Benefits

Potent myostatin inhibitor — removes natural muscle growth limit
Studied for significant lean muscle mass increases
Researched for muscle wasting conditions (sarcopenia, cachexia)
Gene therapy version showed dramatic results in animal models
May support muscle recovery and regeneration

Clinical Evidence Summary

Research Pipeline

Preclinical
Animal
Phase I
Phase II
Phase III
Approved

1

Registered Trials

0

Trial Publications

0

RCT Publications

5

PubMed References

ClinicalTrials.govPubMed ESearchExact-name queryChecked May 3, 2026

Registered trials are ClinicalTrials.gov intervention records. Trial publications are PubMed records tagged as clinical trials or randomized controlled trials. PubMed references are broader source-query matches and can include animal studies, in-vitro work, reviews, mechanism papers, and trial publications.

1

Registered trials

0

Trial publications

0

RCT publications

5

PubMed references

1

Reviews

0

Meta-analyses

Registered trials source

Jun 1, 2026

Follistatin-344

Uses the exact compound name as a ClinicalTrials.gov intervention query.

View source

Publication counts source

May 3, 2026

Follistatin-344

Uses the exact display name.

View source

Not FDA-approved. Gene therapy version (AAV-FS344) in clinical trials for inclusion body myositis and muscular dystrophy. Injectable form is a research compound. Regulatory risk due to gene doping concerns in sports.

Key PubMed References

Safety and Efficacy of Approved and Unapproved Peptide Therapies for Musculoskeletal Injuries and Athletic Performance.

Review

Mendias CL, Awan TM · Sports medicine (Auckland, N.Z.) · 2026

PMID: 41966639

Detection of black market follistatin 344.

Review

Reichel C, Gmeiner G, Thevis M · Drug testing and analysis · 2020

PMID: 33460286

Central serous chorioretinopathy associated with high-dose follistatin-344: a retrospective case series.

Human Study

Dağ U, Çağlayan M, Öncül H, et al. · International ophthalmology · 2020

PMID: 32671599

Detection of black market follistatin 344.

Review

Reichel C, Gmeiner G, Thevis M · Drug testing and analysis · 2019

PMID: 31758732

The transgenic expression of human follistatin-344 increases skeletal muscle mass in pigs.

Animal Study

Chang F, Fang R, Wang M, et al. · Transgenic research · 2017

PMID: 27787698

Anecdotes & Sentiment

Public discussion, not clinical evidence

This section summarizes what people are talking about in public sources. It can be useful for spotting questions, hype cycles, and recurring concerns, but it is separate from the evidence sections above.

No curated public-discussion themes are live for Follistatin-344 yet.

Side Effects & Safety

- Potential effects on reproductive hormones (FSH binding) - Joint and tendon stress from rapid muscle growth - Limited human safety data for injectable form - Theoretical cancer concerns (removing growth regulation) - High cost

Potential effects on reproductive hormones (FSH binding)
Joint and tendon stress from rapid muscle growth
Limited human safety data for injectable form
Theoretical cancer concerns (removing growth regulation)
High cost

Known Interactions

No curated interaction entry is live for Follistatin-344 yet.

Until the interaction table is fully populated, use the interaction checker and related peptides below to explore adjacent compounds and likely research pairings.

Comparison Pages

Comparison pages

All

No comparison page is linked yet.

Frequently Asked Questions

Research Disclaimer

This page is for research and educational purposes only. The information presented is based on published scientific literature and does not constitute medical advice, diagnosis, or treatment recommendations. Regulatory status can vary by compound, formulation, indication, and jurisdiction. Check official labeling, registry records, and qualified professional guidance before making any health-related decision. The studies referenced are linked to their original PubMed sources for verification.