Ipamorelin
Also called Ipamorelin acetate, Ipamorelin (free base), Aib-His-D-2-Nal-D-Phe-Lys-NH2
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In 30 seconds
A lab-made 5-amino-acid peptide that triggers growth hormone release.[1]
Tested in small human studies; a phase 2 trial after bowel surgery found no difference from placebo.[3]
Not FDA-approved and banned in tested sport. FDA's advisers voted against allowing it for compounding.[5][6]
How far has the research gotten?
The molecule
Three of the five aren't among the 20 standard amino acids.
Research over time
Papers on PubMed each year that mention Ipamorelin.0 papers in 2025What studies used
What each paper reports. A record of published research, not a recommendation.Discovery and pharmacology of ipamorelin: potency for growth hormone release compared with GHRP-6 and GHRP-2, receptor pathway, and selectivity (effects on FSH, LH, PRL, TSH, ACTH and cortisol).
European journal of endocrinology · 1998 · PubMed 9849822What the paper reports
Dose-response study; ED50 for GH release 80+/-42 nmol/kg in anaesthetised rats and 2.3+/-0.03 nmol/kg in conscious swine; ACTH/cortisol checked at doses more than 200-fold the ED50
Who: Rat (pituitary cells in vitro and anaesthetised rats); swinePharmacokinetics (half-life, clearance, volume of distribution) and the growth hormone response to ipamorelin, described with a PK/PD model.
Pharmaceutical research · 1999 · PubMed 10496658What the paper reports
15-minute intravenous infusions at 4.21, 14.02, 42.13, 84.27 and 140.45 nmol/kg (dose escalation)
Who: Human (healthy men, 8 per dose level)Phase 2 double-blind, placebo-controlled trial (NCT00672074) of safety and time to tolerating a solid meal after bowel surgery. The abstract reports no significant differences from placebo on key or secondary efficacy measures.
International journal of colorectal disease · 2014 · PubMed 25331030What the paper reports
0.03 mg/kg intravenous infusion twice daily from postoperative day 1 to day 7 or hospital discharge
Who: Human (117 adults enrolled after bowel resection)FDA's list of bulk substances it says may raise significant safety risks if pharmacies compound them. Ipamorelin acetate is on the version of the list for outsourcing facilities.[4]
What it is, in full 4
Ipamorelin is a synthetic five-amino-acid peptide developed by Novo Nordisk researchers that triggers growth hormone release through the same kind of receptor used by the growth hormone-releasing peptides (GHRPs).[1]
In rat and pig experiments it released growth hormone about as strongly as GHRP-6, and in pigs it did not raise ACTH or cortisol beyond the levels seen with GHRH, even at doses more than 200 times its half-maximal dose for growth hormone.[1]
In healthy male volunteers given intravenous infusions, it caused a single burst of growth hormone release and had a terminal half-life of about 2 hours.[2]
A placebo-controlled phase 2 trial of intravenous ipamorelin after bowel surgery found no significant difference from placebo in time to tolerating a solid meal.[3]
Regulatory details 4
Searches of Drugs@FDA (openFDA, active ingredient 'ipamorelin') and DailyMed returned no matches on 2026-10-06. No FDA page opened in this session states its approval status in words.[7]
Checked 2026-10-06FDA's category 2 page lists ipamorelin acetate under 503B category 2, added September 29, 2023. It also appears in the table of substances previously in category 2 whose nominations were withdrawn. FDA's stated concerns: possible immunogenicity from aggregation or peptide impurities, unnatural amino acids that complicate characterization, and a published study that FDA says reported serious adverse events, including death, with intravenous use for gastric motility. Page content current as of 04/22/2026.[4]
Checked 2026-10-06At the October 29, 2024 Pharmacy Compounding Advisory Committee meeting, FDA proposed that ipamorelin (free base) and ipamorelin acetate not be added to the 503A Bulks List. These were reviewed for growth hormone deficiency and postoperative ileus. The vote for each was 0 yes, 12 no, 1 abstain.[5]
Checked 2026-10-06The 2026 Prohibited List names ipamorelin as an example of a growth hormone secretagogue under S2.2.4 Growth hormone releasing factors. S2 substances are prohibited in and out of competition and are non-Specified.[6]
Checked 2026-10-06Human trials on ClinicalTrials.gov
An intervention search of ClinicalTrials.gov for 'ipamorelin' on 2026-10-06 returned 3 records: two completed phase 2 trials of intravenous ipamorelin for gastrointestinal recovery after bowel surgery (NCT00672074 and NCT01280344, the latter sponsored by Helsinn Therapeutics) and one unrelated record that matched the term.[8]
All sources 9
- Raun K et al. Eur J Endocrinol 1998 (PMID 9849822)PubMed / NCBI
- Gobburu JV et al. Pharm Res 1999 (PMID 10496658)PubMed / NCBI
- Beck DE et al. Int J Colorectal Dis 2014 (PMID 25331030)PubMed / NCBI
- Certain Bulk Drug Substances for Use in Compounding that May Present Significant Safety Risks (category 2 page)U.S. Food and Drug Administration
- Final Summary Minutes, Pharmacy Compounding Advisory Committee, October 29, 2024U.S. Food and Drug Administration
- WADA Prohibited List 2026World Anti-Doping Agency
- openFDA Drugs@FDA search: ipamorelin (no matches)U.S. Food and Drug Administration (openFDA)
- ClinicalTrials.gov API intervention search: ipamorelinClinicalTrials.gov / NLM
- DailyMed SPL search: ipamorelin (0 results)DailyMed / NLM
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