# Sermorelin vs ipamorelin - Canonical: https://residue.info/vs/sermorelin-vs-ipamorelin/ - Compounds: Sermorelin (https://residue.info/c/sermorelin/), Ipamorelin (https://residue.info/c/ipamorelin/) - Updated: 2026-10-19 · Reviewed by: Residue Editorial Team Both raise growth hormone, through different receptors. Sermorelin is a GHRH analog acting on the pituitary's GHRH receptor [1]; ipamorelin is a pentapeptide acting on the ghrelin (GH-secretagogue) receptor [2]. Sermorelin was FDA-approved as Geref (now discontinued) [3]. Ipamorelin was never approved, its one randomized efficacy trial was negative [4], and FDA lists it in compounding Category 2 [5]. ## Side by side | | Sermorelin | Ipamorelin | |---|---|---| | Receptor | GHRH receptor [1] | Ghrelin / GH-secretagogue receptor [2] | | Size | 29 amino acids [1] | 5 residues (Aib-His-D-2-Nal-D-Phe-Lys-NH2) [2] | | FDA status | Geref approved; discontinued [3] | Never approved; Category 2 for 503B [5] | | Best human data | Pediatric GH-deficiency trials [6] | One RCT in post-operative ileus, no significant benefit [4] | | Selectivity | Specific stimulation of GH secretion [1] | No change in FSH, LH, prolactin or TSH in swine [2] | | Safety note | Anti-GHRH antibodies in most treated children [6] | FDA cites immunogenicity risk and a reported death with IV use [5] | | Evidence grade | A (historic approval) | C | ## How does each one raise growth hormone? Growth hormone release from the pituitary is driven by more than one signal. Sermorelin reproduces the GHRH signal: it is GHRH(1-29)-NH2 and specifically stimulates GH secretion from the anterior pituitary [1]. Ipamorelin works through the GH-secretagogue receptor targeted by GHRP-6; in rat pituitary cells, anesthetized rats and swine it released GH with potency and efficacy similar to GHRP-6, and in swine it did not change FSH, LH, prolactin or TSH — the basis for describing it as the first selective GH secretagogue [2]. ## What does the human evidence show? **Sermorelin** was studied in children with GH deficiency. In a randomized study of 60 children, mean height velocity at 6 months was 9.2 and 9.3 cm/year on two GHRH doses versus 14.6 cm/year on growth hormone [6]. Its review literature also describes a diagnostic use as an intravenous provocative test [1]. **Ipamorelin**'s only published randomized efficacy trial tested intravenous dosing in 114 patients after bowel resection; median time to first tolerated meal was 25.3 versus 32.6 hours (p=0.15), with no significant differences on any efficacy analysis [4]. Other data are from rats — improved post-operative gut transit [7] and increased longitudinal bone growth [8]. Neither has published randomized data for anti-aging, body-composition or performance uses in the sources we fetched. ## Are they FDA-approved? Sermorelin's Geref applications are discontinued [3][9], and sermorelin does not appear on FDA's Category 2 list [5]. Ipamorelin acetate is in Category 2 for outsourcing facilities [5]. ## Frequently asked questions **Do sermorelin and ipamorelin work the same way?** No. Sermorelin mimics GHRH [1]; ipamorelin acts like GHRP-6 at the GH-secretagogue (ghrelin) receptor [2]. Both end in pituitary growth hormone release. **Has ipamorelin been tested in people?** Its published randomized efficacy trial enrolled 114 bowel-resection patients and found no significant difference from placebo in time to first tolerated meal (25.3 vs 32.6 hours, p=0.15) [4]. **What is FDA's position on ipamorelin?** FDA placed ipamorelin acetate in Category 2 for 503B outsourcing facilities on September 29, 2023, citing immunogenicity risk and a reported death with intravenous use [5]. **Can you take sermorelin and ipamorelin together?** No published randomized trial among our sources tested that stack. They act on different receptors (GHRH vs ghrelin) [1][2], and ipamorelin is on FDA compounding Category 2 [5]. ## Sources [1] Sermorelin: a review of its use in the diagnosis and treatment of children with idiopathic growth hormone deficiency. Prakash A & Goa KL BioDrugs. 1999. https://pubmed.ncbi.nlm.nih.gov/18031173/ [2] Ipamorelin, the first selective growth hormone secretagogue. Raun K et al. Eur J Endocrinol. 1998. https://pubmed.ncbi.nlm.nih.gov/9849822/ [3] Drugs@FDA: GEREF (NDA019863). EMD SERONO; original approval 1990-12-28; Discontinued. https://www.accessdata.fda.gov/scripts/cder/daf/index.cfm?event=overview.process&ApplNo=019863 [4] Prospective, randomized, controlled, proof-of-concept study of the Ghrelin mimetic ipamorelin for the management of postoperative ileus in bowel resection patients. Beck DE et al. Int J Colorectal Dis. 2014. https://pubmed.ncbi.nlm.nih.gov/25331030/ [5] Certain Bulk Drug Substances for Use in Compounding that May Present Significant Safety Risks. U.S. FDA, content current as of 04/22/2026. https://www.fda.gov/drugs/human-drug-compounding/certain-bulk-drug-substances-use-compounding-may-present-significant-safety-risks [6] A comparative study of growth hormone (GH) and GH-releasing hormone(1-29)-NH2 for stimulation of growth in children with GH deficiency. Chen RG et al. Acta Paediatr Suppl. 1993. https://pubmed.ncbi.nlm.nih.gov/8329830/ [7] Efficacy of ipamorelin, a novel ghrelin mimetic, in a rodent model of postoperative ileus. Venkova K et al. J Pharmacol Exp Ther. 2009. https://pubmed.ncbi.nlm.nih.gov/19289567/ [8] Ipamorelin, a new growth-hormone-releasing peptide, induces longitudinal bone growth in rats. Johansen PB et al. Growth Horm IGF Res. 1999. https://pubmed.ncbi.nlm.nih.gov/10373343/ [9] Drugs@FDA: GEREF (NDA020443). EMD SERONO INC; original approval 1997-09-26; Discontinued. https://www.accessdata.fda.gov/scripts/cder/daf/index.cfm?event=overview.process&ApplNo=020443 --- From Residue. 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