Peptide data sheet
Follistatin 344
Performance · FS-344 · Follistatin-344 · FST-344
Verdict
unprovenfor muscle growth in humans
By MrPepTalks Editorial
Reviewed for scientific accuracy · research information, not medical advice
Last updated Reviewed
Quick answer
Follistatin 344 is one natural isoform of the follistatin protein, commonly researched for its ability to bind and neutralize myostatin, a signal that limits muscle size. In animal models, blocking myostatin was associated with larger muscles, and one small gene-therapy trial explored a related approach in people. Human evidence for the research peptide itself is extremely limited, no validated human protocol exists, and it is not FDA-approved.
- Class
- Follistatin isoform / myostatin-binding protein
- Half-life
- Short in circulation (reported in animal work)
- FDA status
- Not FDA-approved; sold for research use only
- WADA banned?
- Yes
Which form actually works?
Research peptide (injectable-grade)
Unproven
The form sold to consumers. Studied mostly in animals; human data on this form is essentially absent, and purity of gray-market supply is unverified.
AAV gene therapy (AAV1-FS344)
Promising
A distinct clinical-research approach that delivers the follistatin gene, studied in early muscular-dystrophy trials. This is a trial intervention, not the peptide vial sold online.
Third-Party Testing & Certificate of Analysis (COA)
A certificate of analysis (COA) is a lab document that reports what a specific batch of material actually contains. Reputable research suppliers publish one for every batch, tied to a lot number you can match against the vial you received.
- HPLC — purity
- High-performance liquid chromatography reports purity as a percentage: how much of the sample is the intended compound rather than impurities.
- Mass spectrometry (MS) — identity
- Mass spectrometry confirms identity by measuring the sample's molecular mass, so it matches the peptide the label names.
It also matters who ran the test. In-house results come from the seller's own lab; an independent third-party lab has no stake in the result, so its COA generally carries more weight. Look for a named testing laboratory, a batch or lot number, and a test date that lines up with the vial in hand.
New to reading one? This guide walks through a COA line by line: how to read a peptide COA.
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