Ipamorelin

Ipamorelin is a synthetic pentapeptide that acts as an agonist at the growth hormone secretagogue receptor (GHS-R1a) — the same receptor the hunger hormone ghrelin binds. Activating this receptor on the pituitary prompts growth hormone release. Where Ipamorelin differs from earlier compounds in its class is cross-reactivity: it shows minimal activity at the pathways governing cortisol and prolactin, and does not meaningfully stimulate appetite. Because it works through a different receptor than GHRH analogs, the two mechanisms are additive when used together, which is the logic behind pairing it with CJC-1295 in Vitality Surge and Tesamorelin in Sculpt Ascent.

Ipamorelin was developed specifically to solve a problem with earlier growth hormone secretagogues, which raised growth hormone but also moved cortisol, prolactin, and appetite along with it. Early human studies confirmed the selectivity: growth hormone rose while those adjacent hormones stayed essentially flat, which is the finding that made it a standard pairing partner for GHRH peptides. Beyond those early studies, the human evidence base is modest — much of the mechanistic work is preclinical, and long-term outcome trials in wellness populations have not been done. Its regulatory position is clearer than most peptides in this category: it was removed from the FDA’s Category 2 list in 2024, so licensed compounding pharmacies can prepare it under prescription. Compounded ipamorelin is not an FDA-approved product.