Ipamorelin — questions, answered plainly.

Ipamorelin is a synthetic pentapeptide (Aib-His-D-2-Nal-D-Phe-Lys-NH2) developed at Novo Nordisk in the late 1990s as a selective growth hormone secretagogue. It binds the ghrelin receptor (GHS-R1a). It is not approved as a medicine.

First-generation growth hormone releasing peptides also stimulated ACTH, cortisol, and prolactin release. The Raun 1998 European Journal of Endocrinology paper (PMID 9849822) characterised ipamorelin as releasing GH in animal models without affecting those other axes — establishing the selectivity claim that defined the compound.

Yes — ipamorelin is classified as a growth hormone releasing peptide (GHRP). It binds the GHS-R1a (ghrelin) receptor, in the same class as the earlier GHRP-2, GHRP-6, and hexarelin.

Yes — the Gobburu 1999 Pharmaceutical Research paper (PMID 10496658) is a Phase I dose-escalation pharmacokinetic study in n=40 healthy male volunteers. It reported dose-proportional pharmacokinetics with a ~2-hour half-life and episodic GH release. No later-stage controlled efficacy trials in humans are cited on this profile.

No. Ipamorelin is not approved by the FDA, MHRA, or EMA at the time of writing. Development was reportedly discontinued at Phase II. The compound exists only in research contexts.

Published human evidence is limited to a single small Phase I pharmacokinetic study. Long-term safety and efficacy in humans have not been established in peer-reviewed literature. The bulk of preclinical evidence is in rats.