Follistatin-344
Myostatin inhibitor (glycoprotein isoform)
Also known as: FS-344, FS344, AAV1-FS344 (gene-therapy construct)
Evidence is limited to animal or in-vitro work. No human pharmacokinetics. Any human dose in circulation is extrapolated, and extrapolation across species routinely fails.
Follistatin-344 is a 344-amino-acid follistatin isoform, not a short injectable peptide; it has been studied as an AAV gene-therapy transgene (e.g., AAV1-FS344), not as a dosed peptide, so conventional peptide pharmacokinetics/half-life do not apply and none are published. Molecular weight left null (protein isoform; no clean value at an allowed primary source).
No peptide dosing exists. Human experience is intramuscular AAV vector dosing (viral genomes), not a microgram peptide dose.
Strong preclinical (mouse, non-human primate) muscle-hypertrophy data and an early-phase human gene-therapy trial; no data supporting an injectable 'follistatin-344 peptide' product.
No boxed warning (unapproved). Gene-therapy-specific risks (vector immunogenicity) apply to the AAV construct. Peptide products marketed as 'Follistatin-344' are not the studied gene therapy and have no clinical safety or PK data.