IGF-DES vs Sermorelin

N-terminal truncation eliminates IGFBP binding, leaving nearly all circulating IGF-DES unbound and active. Results in substantially higher tissue IGF-1R activation versus native IGF-1 at equivalent doses. Activates PI3K/Akt/mTOR for muscle hypertrophy and satellite cell proliferation.

A truncated form of IGF-1 with the first 3 amino acids removed. Does not bind IGF binding proteins (IGFBPs), resulting in dramatically higher free active concentration at tissue level. Considered highly anabolic with limited systemic safety data in humans.

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.