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For research use only. Not for human or veterinary use. Not a drug, food, or dietary supplement.
AMIRAVOResearch Library

Tesamorelin vs ipamorelin

Tesamorelin and ipamorelin both raise growth hormone, but through different receptors: tesamorelin is a GHRH analog and ipamorelin is a GH secretagogue acting through a GHRP-like receptor 1,6. Tesamorelin is FDA-approved for one indication in HIV-associated lipodystrophy, while ipamorelin has no approval and its one efficacy trial did not show benefit over placebo 1,8,10. This page compares their pharmacology, evidence and regulatory status as of 22 October 2026.

Unbranded reference vial illustrating Tesamorelin; not an actual product
Tesamorelin
FDA-approved
Unbranded reference vial illustrating Ipamorelin; not an actual product
Ipamorelin
Not approved — research use only

Side by side

FieldTesamorelinIpamorelin
ClassGHRH (GRF) analog 1GH secretagogue (GHRP-like pentapeptide) 6
Origin and structure44-amino-acid human GRF sequence with an N-terminal hexenoyl group, as an acetate salt 1Synthetic pentapeptide from Novo Nordisk's GH secretagogue program 6
Proposed mechanismBinds and stimulates GRF receptors, increasing GH and then IGF-1 1Releases GH through a GHRP-like receptor 6
Half-lifeMean elimination half-life of 11 minutes (Egrifta WR) and 8 minutes (Egrifta SV) in healthy subjects 1,2Terminal half-life of about 2 hours in healthy men 7
Highest human trial phasePhase 3 randomized trials 3,4Phase 2 randomized trial 8
FDA statusApproved (2010) for reduction of excess abdominal fat in HIV-infected adults with lipodystrophy 1,10Not approved; FDA proposed in 2024 not to add it to the 503A bulks list 9
Published human outcomesIn a 412-patient trial, visceral fat fell 15.2% versus a 5.0% rise with placebo over 26 weeks 3In 117 patients after bowel resection, no significant difference from placebo on efficacy endpoints 8
Safety signalsLabel warnings include elevated IGF-1, fluid retention, glucose intolerance and hypersensitivity 1FDA noted more hypokalemia, insomnia and hyperglycemia in the ipamorelin arm of the ileus trial 9
WADA statusNamed under S2.2.4 as a GHRH analog; prohibited at all times 11Named under S2.2.4 as a GH secretagogue; prohibited at all times 11
Evidence levelLarge randomized phase 3 trials in a specific population 3,4Animal pharmacology, a PK study and one small phase 2 trial 6,7,8

Tesamorelin: what the data says

Tesamorelin consists of the 44-amino-acid sequence of human GRF with a hexenoyl moiety on the N-terminal tyrosine 1. According to the label, it binds GRF receptors with potency similar to endogenous GRF and increases GH, IGF-1 and IGFBP-3 1. Mean elimination half-life was 11 minutes for Egrifta WR and 8 minutes for Egrifta SV in healthy subjects 1,2.

In a 26-week randomized trial in 412 HIV-infected adults with abdominal fat accumulation, visceral adipose tissue decreased by 15.2% with tesamorelin and increased by 5.0% with placebo 3. A pooled analysis of 806 patients in two phase 3 trials reported a change of -24 versus +2 cm2 at week 26 4. A 6-month trial in 50 patients also reported reductions in liver fat 5. The labels state that tesamorelin is not indicated for body-weight management because it has a weight-neutral effect, and that long-term cardiovascular safety has not been established 1,2.

Ipamorelin: what the data says

Ipamorelin is a synthetic pentapeptide that released GH in rat pituitary cells, rats and pigs through a GHRP-like receptor, and in swine it did not raise ACTH or cortisol beyond the levels seen with GHRH (animal data) 6. In healthy men, intravenous infusion produced a single GH episode peaking at 0.67 hours, with a terminal half-life of 2 hours 7.

In a phase 2 randomized, placebo-controlled trial in 117 patients after bowel resection, there were no significant differences between ipamorelin and placebo in key or secondary efficacy analyses 8. FDA's 2024 review found higher rates of hypokalemia and insomnia in the ipamorelin group and said it was unclear whether deaths in treated patients were drug-related 9.

Key research differences

  • Receptor target: tesamorelin acts on GRF (GHRH) receptors, while ipamorelin acts through a GHRP-like (ghrelin-type) receptor 1,6.
  • Approval: tesamorelin is FDA-approved for one HIV-related indication; ipamorelin is not approved 1,9.
  • Evidence base: tesamorelin has phase 3 data in more than 800 patients, while ipamorelin has one small phase 2 trial that did not meet its endpoints 4,8.
  • Half-life: minutes for tesamorelin versus about 2 hours for ipamorelin in healthy subjects 1,7.
  • Both are prohibited in sport under WADA class S2.2.4 11.

Where the evidence is limited

No head-to-head study of tesamorelin and ipamorelin was identified. Tesamorelin's evidence comes from trials in HIV-associated lipodystrophy, and its label covers only that use 1,3,4. Ipamorelin's human data are a pharmacokinetic study in healthy men and one small proof-of-concept trial in surgical patients 7,8. The label notes that the effects of prolonged IGF-1 elevation are unknown 1.

Frequently asked questions

Do tesamorelin and ipamorelin act on the same receptor?
No. Tesamorelin is a GRF (GHRH) analog, while ipamorelin is a GH secretagogue acting through a GHRP-like receptor 1,6.
Is tesamorelin FDA-approved?
Yes, since 2010, for reduction of excess abdominal fat in HIV-infected adults with lipodystrophy 1,10.
Has ipamorelin shown benefit in a clinical trial?
Its phase 2 postoperative ileus trial showed no significant differences from placebo in efficacy analyses 8.
How do their half-lives compare?
Tesamorelin's mean elimination half-life was 8-11 minutes and ipamorelin's terminal half-life was about 2 hours in healthy subjects 1,2,7.
Are they prohibited in sport?
Both are named under S2.2.4 of WADA's 2026 List 11.

References

  1. EGRIFTA WR (tesamorelin) for injection, prescribing information (revised 03/2025) FDA label (DailyMed). 2025
  2. EGRIFTA SV (tesamorelin) for injection, prescribing information FDA label (DailyMed). 2024
  3. Metabolic effects of a growth hormone-releasing factor in patients with HIV New England Journal of Medicine. 2007
  4. Effects of tesamorelin (TH9507), a growth hormone-releasing factor analog, in HIV-infected patients with excess abdominal fat: a pooled analysis of two multicenter, double-blind placebo-controlled phase 3 trials with safety extension data Journal of Clinical Endocrinology & Metabolism. 2010
  5. Effect of tesamorelin on visceral fat and liver fat in HIV-infected patients with abdominal fat accumulation: a randomized clinical trial JAMA. 2014
  6. Ipamorelin, the first selective growth hormone secretagogue European Journal of Endocrinology. 1998
  7. Pharmacokinetic-pharmacodynamic modeling of ipamorelin, a growth hormone releasing peptide, in human volunteers Pharmaceutical Research. 1999
  8. Prospective, 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. 2014
  9. FDA Briefing Document: Ipamorelin-related bulk drug substances, Pharmacy Compounding Advisory Committee, October 29, 2024 FDA. 2024
  10. Drugs@FDA application data queried through openFDA for tesamorelin (EGRIFTA, application 022505, original approval 10 November 2010) (queried 22 October 2026) openFDA / Drugs@FDA. 2026
  11. International Standard: Prohibited List 2026 WADA. 2026

For research use only. Not for human or veterinary use. Not a drug, food, or dietary supplement. This page compares published research and is not medical advice or a recommendation.