Muscle growth peptides
Plain-English guides to 2 peptides used for muscle growth in fitness and recovery.
Follistatin-344
Muscle growth
A peptide that blocks myostatin signaling—discussed for muscle mass but with serious safety unknowns.
On label: Myostatin inhibitor peptide
IGF-1 LR3
Muscle growth
A modified insulin-like growth factor with a longer half-life—highly potent and tightly regulated.
On label: IGF-1 LR3