Ipamorelin and Fat Loss: What Has Been Studied

What the research covers

A PubMed search found no human study of ipamorelin for fat loss. In the one animal study of body fat that the search found, it raised fat in rodent (mouse) groups.

Ipamorelin is a man-made peptide of five amino acids. In rodent (rat) and pig tests, it released growth hormone. The authors found that, like GHRP-6, it acts through a GHRP-like receptor.

In a 2001 study, rodent (mouse) groups got ipamorelin shots under the skin twice a day. Body weight rose about 15 percent by two weeks, then held steady to nine weeks. Fat pads also grew as a share of body weight. In rodent (mouse) groups with normal growth hormone, food intake and blood leptin rose. Growth hormone given on its own did not raise body fat. The authors said the extra fat did not come from growth hormone, and eating more may play a part.

The human trials found looked at other outcomes. In 1999, healthy men got one 15-minute IV drip at one of five doses. Growth hormone peaked once, at about 40 minutes. Ipamorelin's half-life in the blood was about 2 hours. A 2014 trial enrolled 117 adults after bowel surgery, and 114 were analysed. They got 0.03 mg/kg by IV drip or a placebo, twice a day for up to 7 days. It was well tolerated, but it did no better than placebo. ClinicalTrials.gov listed no ipamorelin trial for obesity or weight on 27 September 2026.

Sources

1. Gobburu JV, Agersø H, Jusko WJ, et al. Pharmacokinetic-pharmacodynamic modeling of ipamorelin, a growth hormone releasing peptide, in human volunteers Pharm Res (1999). PMID 10496658 doi:10.1023/a:1018955126402 Healthy men, single 15-minute IV infusions at five dose levels; half-life 2 hours. No fat outcome.
2. Beck DE, Sweeney WB, McCarter MD, et al. Prospective, randomized, controlled, proof-of-concept study of the Ghrelin mimetic ipamorelin for the management of postoperative ileus in bowel resection patients Int J Colorectal Dis (2014). PMID 25331030 doi:10.1007/s00384-014-2030-8 Phase 2 trial, 114 adults after bowel surgery, 0.03 mg/kg IV twice daily; no difference from placebo. No fat outcome.
3. Lall S, Tung LY, Ohlsson C, et al. Growth hormone (GH)-independent stimulation of adiposity by GH secretagogues Biochem Biophys Res Commun (2001). PMID 11162489 doi:10.1006/bbrc.2000.4065 Rodent (mouse) study: twice-daily injections under the skin raised body weight and relative fat mass.
4. Raun K, Hansen BS, Johansen NL, et al. Ipamorelin, the first selective growth hormone secretagogue Eur J Endocrinol (1998). PMID 9849822 doi:10.1530/eje.0.1390552 Rodent (rat) and pig study: growth hormone release via a GHRP-like receptor; no ACTH or cortisol rise in pigs.