Ipamorelin
Ipamorelin Acetate
A selective growth hormone secretagogue and ghrelin receptor agonist that stimulates pulsatile GH release with minimal effect on cortisol or prolactin.
Overview
Ipamorelin is one of the most selective GH secretagogues studied. It prompts the pituitary to release growth hormone in a pulsatile pattern without significantly raising cortisol, prolactin, or ACTH. It is frequently discussed in research alongside CJC-1295. It is not an approved drug.
Mechanism of action
Agonizes the ghrelin/GH secretagogue receptor (GHS-R1a) on the pituitary, stimulating pulsatile growth hormone secretion.
Key studies & citations
- Animal1998
Ipamorelin, the first selective growth hormone secretagogue
Pentapeptide with GH-releasing potency similar to GHRP-6 in rat pituitary cells, rats and swine, acting through a GHRP-like receptor; the paper that defined ipamorelin's selectivity profile.
European Journal of Endocrinology - Human2014
Prospective, randomized, controlled, proof-of-concept study of the ghrelin mimetic ipamorelin for the management of postoperative ileus in bowel resection patients
Phase 2 RCT in 117 surgical patients (NCT00672074): IV ipamorelin was well tolerated but did not significantly shorten time to first tolerated meal versus placebo (25.3 vs 32.6 h, p=0.15).
International Journal of Colorectal Disease - In vitro1996
A receptor in pituitary and hypothalamus that functions in growth hormone release
Cloning of the growth hormone secretagogue receptor (GHS-R) in pituitary and hypothalamus, the target through which ipamorelin and other GHRPs act.
Science
Frequently asked questions
Why is ipamorelin considered selective?
In studies it raises growth hormone without meaningfully increasing cortisol or prolactin, unlike some earlier GH secretagogues.