Follistatin 344 vs Sermorelin

Binds and neutralizes myostatin (GDF-8) and activin; removes the natural brake on muscle growth allowing supraphysiological hypertrophy

A myostatin inhibitor that removes the natural limit on muscle growth. Produces dramatic increases in muscle mass and strength by blocking TGF-β family proteins.

Sermorelin is a synthetic analogue of the first 29 amino acids of endogenous growth hormone-releasing hormone (GHRH). It binds to GHRH receptors on pituitary somatotrophs, stimulating pulsatile GH secretion in a physiological pattern that preserves the natural hypothalamic-pituitary feedback axis — contrasting with direct GH administration. Downstream IGF-1 elevation mediates many of its body composition, tissue-repair, and sleep quality effects.

Sermorelin is a GHRH analogue used to stimulate endogenous growth hormone production. It is one of the most widely prescribed peptides in the anti-aging and functional medicine space, valued for preserving the natural pituitary feedback axis while supporting body composition, sleep quality, and tissue repair. Compounded formulations are available in the US through 503A pharmacies.