Pinc PeptideThe girly peptide research blog

Compare · updated 8 October 2026

Ipamorelin vs Sermorelin

The short answer

We found no study that compared them, so neither can be shown to be better12. Sermorelin has the stronger human record: as Geref it was an FDA-approved medicine for children who make too little growth hormone, and it sped their growth, though growth hormone itself did as well or better4567. Ipamorelin was never approved, and its only published patient trial, in adults recovering from bowel surgery, found no clear benefit89. For anti-aging, fat loss or sleep in healthy adults, the evidence for either is thin or missing91011.

At a glance

ComparedIpamorelinSermorelin
Evidence tierB At least one controlled human trialB At least one controlled human trial
Does it work?For fat loss, muscle and sleep: UntestedAn IV dose triggers a short burst of growth hormone12, but we found no study in people of fat loss, muscle or sleep913. Its only published patient trial, after bowel surgery, found no clear benefit8.For anti-aging: Mixed resultsIn a 6-month trial against placebo in 89 older adults, some thinking tests improved14. The team’s other reports found less body fat but no better sleep, and said routine use was not yet supported1011.
FDANot approved for any use9No longer approved (Geref, withdrawn 2009)41516
US pharmaciesPharmacies may not make it171819Pharmacies can probably make it on prescription17181920
SportBanned at all times2122Banned at all times2122
AustraliaPrescription only; illegal to hold without one23Prescription only23
Half-lifeAbout 2 hours after an IV dose; none found for other routes12About 4 minutes (4.3 ± 1.4 min, mean ± SE)24
Taken asIntravenous infusion (the only route with published clinical data we found: healthy volunteers and surgery patients)
Subcutaneous injection (the usual clinic and gray-market route; we found no published human studies, only adverse-event reports)
Nasal spray (sold by compounders per FDA; about 20% absorbed in rats; one volunteer in an anti-doping study)
Oral tablets and troches (advertised by clinics per FDA’s 2024 review; no human data found)		Subcutaneous injection (the approved treatment route; most human data)
Intravenous injection (the approved diagnostic test; pharmacology studies)
Continuous infusion (pediatric trials)
Intranasal (studied in healthy men, only 3 to 5% absorbed, and in a small pilot in children)
Oral tablets (sold by compounders; no human data found)
What it isA lab-made chain of 5 amino acids, 3 of them building blocks not found in human proteins as such; it belongs to the growth-hormone-releasing peptide (GHRP) family925.A lab-made copy of the first 29 of the 44 amino acids of GHRH (growth-hormone-releasing hormone), the brain hormone that tells the pituitary gland to release growth hormone2627.
How it raises growth hormoneSwitches on the ghrelin receptor, the same switch the ‘hunger hormone’ ghrelin uses, in the brain and pituitary9.Switches on the pituitary’s GHRH receptor, as the natural hormone does; FDA calls this 29-amino-acid piece ‘a fully functional sequence’2829.
Effect on growth hormone in peopleOne IV dose in healthy men caused a single growth hormone burst that peaked at about 40 minutes and fell to very low levels within about 6 hours912.Growth hormone stayed raised for about 3 hours after an IV dose; in 10 older men, 14 days of twice-daily injections at the higher of two doses raised 24-hour growth hormone and IGF-1, a growth factor, to young-adult levels3031.
Studied in people forGut recovery after bowel surgery, given by vein in hospital, plus one study of blood levels in 40 healthy men; FDA found no human studies of injection under the skin, nasal or oral use8912.Growth in children who make too little growth hormone (its former approved use), a diagnostic test of the pituitary, and aging in healthy older adults4514.
Strongest human evidenceA placebo-controlled trial in 114 adults after bowel surgery: median time to a solid meal was 25.3 hours vs 32.6 on placebo, not a significant difference8; a 320-patient trial finished in 2014 but has posted no results, and we found no publication of them1332.In an open study of 110 children who make too little growth hormone, average growth rose from 4.1 to 8.0 cm a year at 6 months (86 analyzed); in a randomized trial of 60 children, growth hormone gave 14.6 cm a year vs 9.2 and 9.3 cm on two sermorelin doses57.
Biggest documented riskIn the surgery trial, low potassium (12.5% vs 3.4%) and high blood sugar at discharge (14.3% vs 8.6%) were more common than on placebo, and 2 of 56 patients on it died; FDA says the link is unclear89.Flushing and injection-site pain were the most common side effects in children, 39 of 40 children in one trial made antibodies to it, and FDA’s database holds unverified reports of severe allergic reactions73334.
Product quality problems52 of the latest 200 tests of gray-market vials by Finnrick, an independent testing service, failed (11 December 2025 to 24 September 2026)35.FDA lists 92 recalled sermorelin products from 2012 to 2025, 81 of them for sterility problems, and 27 of 48 completed Finnrick tests failed (20 April 2025 to 14 September 2026)3637.

How do they raise growth hormone differently?

A 2026 review puts them in different classes: GHRH analogues such as sermorelin switch on the pituitary’s GHRH receptor, while growth-hormone-releasing peptides such as ipamorelin switch on the ghrelin receptor29. Ipamorelin’s developers called it the first ‘selective’ growth hormone secretagogue, a drug that makes the body release growth hormone: in pigs it did not raise the stress hormones ACTH and cortisol, unlike GHRP-2 and GHRP-6, older peptides in its family25.

Both work only if the pituitary can still make growth hormone: FDA says people with complete growth hormone deficiency will not respond to secretagogues, the group in which it places both drugs9. With sermorelin, the body’s own brakes stay on, because IGF-1 feeds back to limit further growth hormone release11.

A 2003 review of the two drug types in older adults found that each, given repeatedly, raised IGF-1 into the normal range for younger adults10. It found that GHRH, given for several months, increased lean (muscle) mass and reduced body fat, while ghrelin-mimicking drugs, the class ipamorelin belongs to, had not yet been shown to reduce fat10. Its authors concluded that the results did not yet support routine use of either type in normal aging10.

How do their FDA histories differ?

FDA approved sermorelin, sold as Geref, on 28 December 1990 as a test of whether the pituitary can release growth hormone, and on 26 September 1997 to treat children with growth failure from growth hormone deficiency415. In 2008 its maker, EMD Serono, told FDA it was discontinuing both products, and FDA withdrew the approvals effective 18 June 20091516.

In 2013 FDA found that Geref was not withdrawn for reasons of safety or effectiveness, which lets FDA approve generic versions that meet its other requirements, but as of 29 September 2026 Drugs@FDA listed none415. FDA’s 2024 review of ipamorelin notes that among secretagogues, only sermorelin was approved to treat short stature in children with growth hormone deficiency9.

Ipamorelin was never approved: Novo Nordisk researchers first made it in the mid-1990s, Helsinn Therapeutics tested it after bowel surgery from 2008 to 2014, and a 2020 paper quoted by FDA says development stopped after disappointing results9253238. On 29 October 2024 FDA’s advisers voted 0-12, with 1 abstention, against letting pharmacies compound it, and on 24 August 2026 FDA warned two online sellers that their tesamorelin and ipamorelin blends were unapproved drugs394041.

Is there evidence for taking them together?

No: as of 7 October 2026, the 5 PubMed records that match both names are reviews, and no trial of the pair is registered on ClinicalTrials.gov12. The closest evidence is a 2009 hormone study in 47 men that infused GHRH, the hormone sermorelin copies part of, together with GHRP-2, an older peptide from ipamorelin’s family325. The pair caused a combined surge in growth hormone, an effect called synergy, which was weaker in older men and in men with more belly fat; the study measured hormone release, not changes in muscle, fat or health3.

A 2017 chart review found that average IGF-1 rose from 159.5 to 239.0 ng/mL in 14 men on testosterone who took sermorelin with GHRP-2 and GHRP-6, not ipamorelin; it had no control group42.

Blends are sold online and have been made by compounders93643. Two outsourcing facilities, large compounders registered with FDA, reported making sermorelin-plus-ipamorelin injections, one from 2017 to 2019 and the other from 2019 to 20209. A Texas compounder recalled a sermorelin/ipamorelin injection in 2021 for lack of sterility assurance44. FDA’s adverse-event database holds a report of a 46-year-old man who injected an ipamorelin-sermorelin product for 2 months and had elbow pain, and FDA said that with two peptides in the product it could not assess whether ipamorelin was responsible9.

Questions people ask

Is sermorelin better than ipamorelin?

Sermorelin has more human evidence, mostly from children who make too little growth hormone, in whom it sped growth, although growth hormone itself did as well or better567. We found no published patient trial in which ipamorelin helped81332. We found no study that compared the two directly12.

Can you take ipamorelin and sermorelin together?

We found no published or registered study of the pair, so its benefits and risks are unknown12. In a 2009 study, related drugs given together caused a combined growth hormone surge, but it did not test any health effect3.

Is ipamorelin or sermorelin better for sleep?

Neither has been shown to improve sleep: in older adults, an early analysis found slightly worse self-rated sleep after months of nightly sermorelin, which the investigators said might be nonspecific11, and a 2003 review found that long-term use of a short-acting GHRH did not improve sleep10. We found no study of ipamorelin for sleep, and in its surgery trial insomnia was more common on it than on placebo (10.7% vs 5.2%)913.

Why was sermorelin discontinued?

Its maker, EMD Serono, told FDA in 2008 that it was discontinuing Geref, and FDA withdrew the approvals effective 18 June 2009; FDA’s notices do not give the company’s reason1516. In 2013 FDA found that the drug was not withdrawn for reasons of safety or effectiveness15.

Go deeper

Sources

  1. 1PubMed search: ipamorelin AND sermorelin (5 results, all reviews) National Library of Medicine (PubMed), accessed 7 Oct 2026. pubmed.ncbi.nlm.nih.gov
  2. 2ClinicalTrials.gov search for ‘ipamorelin AND sermorelin’ (0 studies) ClinicalTrials.gov, accessed 7 Oct 2026. clinicaltrials.gov
  3. 3Determinants of GH-releasing hormone and GH-releasing peptide synergy in men American Journal of Physiology: Endocrinology and Metabolism, May 2009. pubmed.ncbi.nlm.nih.gov
  4. 4Drugs@FDA records for sermorelin acetate (Geref, NDA 019863 and NDA 020443), via the openFDA API U.S. Food and Drug Administration (openFDA), 29 Sep 2026. api.fda.gov · data query
  5. 5Once daily subcutaneous growth hormone-releasing hormone therapy accelerates growth in growth hormone-deficient children during the first year of therapy (Geref International Study Group) The Journal of Clinical Endocrinology & Metabolism, Mar 1996. pubmed.ncbi.nlm.nih.gov
  6. 6Growth response to growth hormone-releasing hormone(1-29)-NH2 compared with growth hormone Acta Paediatrica Supplement, Mar 1993. pubmed.ncbi.nlm.nih.gov
  7. 7A comparative study of growth hormone (GH) and GH-releasing hormone(1-29)-NH2 for stimulation of growth in children with GH deficiency Acta Paediatrica Supplement, Mar 1993. pubmed.ncbi.nlm.nih.gov
  8. 8Prospective, randomized, controlled, proof-of-concept study of the Ghrelin mimetic ipamorelin for the management of postoperative ileus in bowel resection patients International Journal of Colorectal Disease, Dec 2014. pubmed.ncbi.nlm.nih.gov
  9. 9FDA Briefing Document, Pharmacy Compounding Advisory Committee meeting of October 29, 2024: ipamorelin-related bulk drug substances (FDA evaluation dated 19 August 2024) U.S. Food and Drug Administration, 19 Aug 2024. fda.gov
  10. 10Growth hormone-releasing hormone and growth hormone secretagogues in normal aging Endocrine, Oct 2003. pubmed.ncbi.nlm.nih.gov
  11. 11Treating age-related changes in somatotrophic hormones, sleep, and cognition Dialogues in Clinical Neuroscience, Sep 2001. pmc.ncbi.nlm.nih.gov
  12. 12Pharmacokinetic-pharmacodynamic modeling of ipamorelin, a growth hormone releasing peptide, in human volunteers Pharmaceutical Research, Sep 1999. pubmed.ncbi.nlm.nih.gov
  13. 13PubMed search: ipamorelin (54 results) National Library of Medicine (PubMed), accessed 8 Oct 2026. pubmed.ncbi.nlm.nih.gov
  14. 14Growth hormone releasing hormone improves the cognition of healthy older adults Neurobiology of Aging, Feb 2006. pubmed.ncbi.nlm.nih.gov
  15. 15Determination That GEREF (Sermorelin Acetate) Injection, 0.5 Milligrams Base/Vial and 1.0 Milligrams Base/Vial, and GEREF (Sermorelin Acetate) Injection, 0.05 Milligrams Base/Amp, Were Not Withdrawn From Sale for Reasons of Safety or Effectiveness (78 FR 14095) Federal Register (U.S. Food and Drug Administration), 4 Mar 2013. federalregister.gov
  16. 16Novartis Pharmaceuticals Corp. et al.; Withdrawal of Approval of 92 New Drug Applications and 49 Abbreviated New Drug Applications (74 FR 23407) Federal Register (U.S. Food and Drug Administration), 19 May 2009. federalregister.gov
  17. 17Bulk Drug Substances Nominated for Use in Compounding Under Section 503A of the Federal Food, Drug, and Cosmetic Act (categories list) U.S. Food and Drug Administration, 14 May 2026. fda.gov
  18. 18Certain Bulk Drug Substances for Use in Compounding that May Present Significant Safety Risks U.S. Food and Drug Administration, 22 Apr 2026. fda.gov
  19. 19Bulk Drug Substances Nominated for Use in Compounding Under Section 503B of the Federal Food, Drug, and Cosmetic Act (categories list) U.S. Food and Drug Administration, 21 Mar 2025. fda.gov
  20. 20Bulk Drug Substances Used in Compounding Under Section 503A of the FD&C Act U.S. Food and Drug Administration, 14 May 2026. fda.gov
  21. 21World Anti-Doping Code International Standard: Prohibited List 2026 World Anti-Doping Agency, 24 Sep 2025. wada-ama.org
  22. 22World Anti-Doping Code International Standard: Prohibited List 2027 World Anti-Doping Agency, 21 Sep 2026. wada-ama.org
  23. 23Therapeutic Goods (Poisons Standard—October 2026) Instrument 2026 (F2026L01327) Federal Register of Legislation, Australian Government, 28 Sep 2026. legislation.gov.au
  24. 24Incorporation of D-Ala2 in growth hormone-releasing hormone-(1-29)-NH2 increases the half-life and decreases metabolic clearance in normal men The Journal of Clinical Endocrinology & Metabolism, Oct 1994. pubmed.ncbi.nlm.nih.gov
  25. 25Ipamorelin, the first selective growth hormone secretagogue European Journal of Endocrinology, Nov 1998. pubmed.ncbi.nlm.nih.gov
  26. 26UniProtKB P01286 (SLIB_HUMAN): somatoliberin, human growth hormone-releasing hormone precursor UniProt Consortium, 2 Sep 2026. uniprot.org
  27. 27Sermorelin, PubChem compound record (CID 16132413): formula and molecular weight PubChem (U.S. National Library of Medicine), accessed 1 Oct 2026. pubchem.ncbi.nlm.nih.gov
  28. 28FDA Briefing Document, Pharmacy Compounding Advisory Committee meeting of December 4, 2024: CJC-1295-related bulk drug substances U.S. Food and Drug Administration, 15 Nov 2024. fda.gov
  29. 29The emerging landscape of performance-enhancing peptides modulating GH-IGF1 axis: bridging the gap between clinical evidence and patient self-administration Frontiers in Endocrinology, 18 Jun 2026. pmc.ncbi.nlm.nih.gov
  30. 30Growth hormone (GH)-releasing hormone-(1-29) twice daily reverses the decreased GH and insulin-like growth factor-I levels in old men The Journal of Clinical Endocrinology & Metabolism, Aug 1992. pubmed.ncbi.nlm.nih.gov
  31. 31Pharmacokinetics of growth hormone-releasing hormone(1-29)-NH2 and stimulation of growth hormone secretion in healthy subjects after intravenous or intranasal administration Acta Paediatrica Supplement, Mar 1993. pubmed.ncbi.nlm.nih.gov
  32. 32Safety and Efficacy of Ipamorelin Compared to Placebo for the Recovery of Gastrointestinal Function (NCT01280344) ClinicalTrials.gov, 13 Apr 2017. clinicaltrials.gov
  33. 33Sermorelin: a review of its use in the diagnosis and treatment of children with idiopathic growth hormone deficiency BioDrugs, Aug 1999. pubmed.ncbi.nlm.nih.gov
  34. 34FDA Adverse Event Reporting System (FAERS) reports naming a sermorelin product, via the openFDA drug/event API U.S. Food and Drug Administration (openFDA), 30 Jul 2026. api.fda.gov · data query
  35. 35Ipamorelin: safety testing results and vendor ratings Finnrick, 24 Sep 2026. finnrick.com
  36. 36FDA drug recall (enforcement report) records naming sermorelin, via the openFDA drug/enforcement API U.S. Food and Drug Administration (openFDA), 23 Sep 2026. api.fda.gov · data query
  37. 37Sermorelin: safety testing results and vendor ratings Finnrick, 14 Sep 2026. finnrick.com
  38. 38Safety and Efficacy of Ipamorelin for Management of Post-Operative Ileus (NCT00672074) ClinicalTrials.gov, 14 Apr 2017. clinicaltrials.gov
  39. 39Final Summary Minutes of the Pharmacy Compounding Advisory Committee Meeting, October 29, 2024 U.S. Food and Drug Administration, 15 Jan 2025. fda.gov
  40. 40Warning letter to Royal Peptides LLC (MARCS-CMS 734884) U.S. Food and Drug Administration, 24 Aug 2026. fda.gov
  41. 41Warning letter to NuScience Peptides LLC (MARCS-CMS 733652) U.S. Food and Drug Administration, 24 Aug 2026. fda.gov
  42. 42Growth Hormone Secretagogue Treatment in Hypogonadal Men Raises Serum Insulin-Like Growth Factor-1 Levels American Journal of Men’s Health, Nov 2017. pubmed.ncbi.nlm.nih.gov
  43. 43Core Peptides shop page sorted by popularity Core Peptides (vendor), accessed 1 Oct 2026. corepeptides.com (seller page, deliberately not linked)
  44. 44Warning letter to Innoveix Pharmaceuticals, Inc. (MARCS-CMS 624782) U.S. Food and Drug Administration, 26 Jan 2022. fda.gov

Not medical advice. Neither compound is recommended here. How we grade evidence · Report an error.