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Sermorelin vs ipamorelin

A Sermorelin GHRH receptor agonist at the anterior pituitary Approved product discontinued (Geref) C Ipamorelin Ghrelin-receptor (GH-secretagogue receptor) agonist Not FDA-approved · FDA compounding Category 2 (503B)

Residue Editorial Team · updated

In brief

Both raise growth hormone, through different receptors. Sermorelin is a GHRH analog acting on the pituitary's GHRH receptor1PubMedSermorelin: a review of its use in the diagnosis and treatment of children with idiopathic growth hormone deficiency. Prakash A & Goa KL BioDrugs. 1999.; ipamorelin is a pentapeptide acting on the ghrelin (GH-secretagogue) receptor2PubMedIpamorelin, the first selective growth hormone secretagogue. Raun K et al. Eur J Endocrinol. 1998.. Sermorelin was FDA-approved as Geref (now discontinued)3FDADrugs@FDA: GEREF (NDA019863). EMD SERONO; original approval 1990-12-28; Discontinued.. Ipamorelin was never approved, its one randomized efficacy trial was negative4PubMedProspective, 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., and FDA lists it in compounding Category 25FDACertain Bulk Drug Substances for Use in Compounding that May Present Significant Safety Risks. U.S. FDA, content current as of 04/22/2026..

How do Sermorelin and Ipamorelin compare at a glance?

Table 1. Sermorelin and Ipamorelin on the dimensions that matter most; every entry is cited.
DimensionSermorelinIpamorelin
ReceptorGHRH receptor1Ghrelin / GH-secretagogue receptor2
Size29 amino acids15 residues (Aib-His-D-2-Nal-D-Phe-Lys-NH2)2
FDA statusGeref approved; discontinued3Never approved; Category 2 for 503B5
Best human dataPediatric GH-deficiency trials6PubMedA 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.One RCT in post-operative ileus, no significant benefit4
SelectivitySpecific stimulation of GH secretion1No change in FSH, LH, prolactin or TSH in swine2
Safety noteAnti-GHRH antibodies in most treated children6FDA cites immunogenicity risk and a reported death with IV use5
Evidence gradeA (historic approval)C

Written by Residue Editorial Team

Reviewed by Residue Editorial Team · source-by-source check,

First published

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Registry data · How we grade · Markdown + sources

Figure 1. Size of the research record, from PubMed and ClinicalTrials.gov at the data edition. Bars are scaled to the larger value in each row; volume is not quality.
PubMed records 366 51
Trial publications 63 2
Registered studies 27 3
Phase 3 studies 4 0

Sermorelin Ipamorelin

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 pituitary1. 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 secretagogue2.

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 hormone6. Its review literature also describes a diagnostic use as an intravenous provocative test1.

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 analysis4. Other data are from rats — improved post-operative gut transit7PubMedEfficacy of ipamorelin, a novel ghrelin mimetic, in a rodent model of postoperative ileus. Venkova K et al. J Pharmacol Exp Ther. 2009. and increased longitudinal bone growth8PubMedIpamorelin, a new growth-hormone-releasing peptide, induces longitudinal bone growth in rats. Johansen PB et al. Growth Horm IGF Res. 1999..

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 discontinued3,9FDADrugs@FDA: GEREF (NDA020443). EMD SERONO INC; original approval 1997-09-26; Discontinued., and sermorelin does not appear on FDA's Category 2 list5. Ipamorelin acetate is in Category 2 for outsourcing facilities5.

Two identical glass beakers, one holding pale amber liquid and one clear, standing either side of a brass balance

Why do they get these evidence grades?

A Sermorelin
Was FDA-approved (Geref, now discontinued) on pediatric data. Evidence for adult or anti-aging uses is limited and graded separately below. Grade A: Approved / regulatory-grade.
C Ipamorelin
One small randomized proof-of-concept trial (postoperative ileus) showed no significant benefit; the rest of the record is animal and pharmacology work. Grade C: Limited / early human data.

Questions readers ask

Do sermorelin and ipamorelin work the same way?

No. Sermorelin mimics GHRH1; ipamorelin acts like GHRP-6 at the GH-secretagogue (ghrelin) receptor2. 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 use5.

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 25.

References

Every source below was retrieved from its official API or page and cached on the data-edition date. Numbers match the margin notes.

  1. 1 PubMed Prakash A, Goa KL. Sermorelin: a review of its use in the diagnosis and treatment of children with idiopathic growth hormone deficiency. BioDrugs 1999. PMID 18031173; doi:10.2165/00063030-199912020-00007.
  2. 2 PubMed 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.
  3. 3 FDA Drugs@FDA: GEREF (NDA019863). EMD SERONO; original approval 1990-12-28; Discontinued.
  4. 4 PubMed 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.
  5. 5 FDA Certain Bulk Drug Substances for Use in Compounding that May Present Significant Safety Risks. U.S. FDA, content current as of 04/22/2026.
  6. 6 PubMed Chen RG, Shen YN, Yei J, et al. A comparative study of growth hormone (GH) and GH-releasing hormone(1-29)-NH2 for stimulation of growth in children with GH deficiency. Acta Paediatr Suppl 1993. PMID 8329830; doi:10.1111/j.1651-2227.1993.tb12834.x.
  7. 7 PubMed Venkova K, Mann W, Nelson R, et al. Efficacy of ipamorelin, a novel ghrelin mimetic, in a rodent model of postoperative ileus. J Pharmacol Exp Ther 2009. PMID 19289567; doi:10.1124/jpet.108.149211.
  8. 8 PubMed Johansen PB, Nowak J, Skjaerbaek C, et al. Ipamorelin, a new growth-hormone-releasing peptide, induces longitudinal bone growth in rats. Growth Horm IGF Res 1999. PMID 10373343; doi:10.1054/ghir.1999.9998.
  9. 9 FDA Drugs@FDA: GEREF (NDA020443). EMD SERONO INC; original approval 1997-09-26; Discontinued.