Overview. Ipamorelin is a synthetic peptide studied as a growth hormone secretagogue — a substance that stimulates the release of growth hormone through a mechanism distinct from GHRH analogues such as tesamorelin.
Molecule / class. Ipamorelin is a pentapeptide, and was described in the scientific literature as the first growth hormone secretagogue with selectivity for GH release comparable to that of GHRH, while acting through a different receptor.
Mechanism under investigation. Ipamorelin binds and activates the growth hormone secretagogue receptor, subtype 1a (GHS-R1a) — the same receptor activated by ghrelin, the endogenous hormone best known for its role in hunger signaling and GH release. This is a mechanistically distinct pathway from a GHRH analogue like tesamorelin, which acts on the separate GHRH receptor; researchers have studied both as different entry points into the same broader GH/IGF-1 axis.
Why the pathway is researched. The ghrelin/GH pathway is of research interest for its role in growth hormone regulation and, separately, appetite and energy balance; studying a selective agonist at this receptor lets researchers isolate that specific mechanism from others acting on the same downstream hormone.
Research status. Preclinical data on ipamorelin exists in the published literature. Human research specific to ipamorelin is limited; one Phase 2 randomized controlled trial studying it for a specific post-surgical condition did not meet its endpoint.
Regulatory status. Ipamorelin has never received FDA approval for any indication and is not an approved drug in the United States. Its status specifically as a substance eligible for pharmacy compounding under Section 503A of the Federal Food, Drug, and Cosmetic Act has changed more than once as FDA has reviewed nominations to its bulk drug substances lists — rather than state a specific snapshot here that may already be out of date, the current, authoritative status is published directly by the FDA (linked below).
What remains unknown. Ipamorelin’s effects, safety profile, and appropriate use are not established through the kind of large-scale human clinical trial program that supports an approved medicine.
NuePharma product information. NuePharma’s Ipamorelin listing is 10 mg per vial, supplied lyophilized, for research use only.