Follistatin 344
PreclinicalA muscle-gene blocker with genuine science behind it, but no human performance trials, a broad off-target profile, and a market full of questionable vials.
What it is
Follistatin 344 is a large protein, a version of the natural follistatin your body already makes. It is famous in muscle circles because it inactivates myostatin, the protein that acts as a brake on muscle size. Without that brake, muscle can grow dramatically.
How it works
Follistatin grabs and neutralizes myostatin and several related signaling proteins in the same family, which control cell division and growth across many tissues, not just muscle. That is why the biology is broader than the 'myostatin blocker' marketing suggests, and why its effects are not limited to muscle.
What people report
- ✦The myostatin pathway is real: animals and rare humans lacking it show striking muscle growth
- ✦A legitimate gene-therapy trial in muscular dystrophy showed real functional benefit
- ✦The theoretical ceiling for muscle looks enormous
- ✦Captures the imagination with famous 'double-muscled cattle' examples
Typical use
Gray-market use is typically a few injections per week. There are no human performance trials and no pharmacokinetic or safety data to guide scheduling.
Dosing reference
No approved dose. The legitimate research path uses gene therapy to have the body produce follistatin, which is completely different from injecting the protein. Verify any vial extremely carefully, since independent testing often finds inconsistent or absent follistatin content.
Reference only — not a recommendation. Verify via primary sources.
Watch for
Three problems stack up. Its off-target effects touch cell proliferation in many tissues, not just muscle, which is a real concern. There are zero human trials at performance doses. And reliably making a 344-amino-acid protein at gray-market scale is rare, so many vials simply are not what they claim. Serious researchers are turning to monoclonal antibodies instead.
Notes
You may be taking something with unstudied proliferation effects, or a vial of something else entirely. Neither is a good option.
Educational content — not medical advice.