A to Z / Growth hormone
Follistatin-344
Also known as FS-344, follistatin.
Best known for The myostatin blocker studied through gene therapy
Evidence★☆☆☆☆
Safety dataLargely unknown
Route Injectable
United StatesNot approved
AustraliaAppendix D cl.5: possession without authority illegal (named individually)
as at 16 September 2026
What it is
Follistatin is a naturally occurring protein that binds and inhibits myostatin, the body's brake on muscle growth. Follistatin-344 is a synthetic variant, discussed mainly for muscle building. It is not approved, and there are no human trials of the injected form.
What the full entry covers
The book carries the rest of this entry:
- Where the research stands, with every claim cited
- What people commonly ask, and what the research shows so far
- Dosing in four labelled bands, described and not recommended
- Side effects, serious risks, cautions and interactions
- Questions to discuss with your doctor
- How it compares with IGF-1 LR3, Somatropin, MK-677
Related entries
A certificate of analysis tells you what is in a vial. The evidence rating above tells you whether the compound has been shown to work in humans. Neither answers the other's question. How to read a certificate of analysis.
This page describes what is known and not known about Follistatin-344. It is not medical advice and not a recommendation to use it.