Ipamorelin and tesamorelin are often searched together because both are studied for increasing the body's own growth hormone release rather than supplying growth hormone directly. They reach the pituitary gland through different receptors, and only one of them is an approved medicine: tesamorelin is FDA-approved as Egrifta for HIV-associated lipodystrophy, while ipamorelin is not FDA-approved.
At a glance
| Ipamorelin | Tesamorelin | |
|---|---|---|
| What it is | Selective growth hormone secretagogue studied for stimulating GH release without raising cortisol or prolactin | Stabilized GHRH analog, FDA-approved as Egrifta for visceral fat in HIV-associated lipodystrophy |
| How it's thought to work | Acts on the ghrelin receptor to stimulate GH release without significantly affecting cortisol, prolactin, or ACTH | Stimulates pulsatile GH release, raising IGF-1 and preferentially mobilizing visceral abdominal fat |
| Regulatory status | Not FDA-approved; a research compound | FDA-approved for HIV-associated lipodystrophy specifically; other uses are off-label |
| Strength of evidence | Clinical studies show selective GH release; formal human trial data beyond that is limited | Multiple human clinical trials support visceral fat reduction; basis for FDA approval |
| Reported side effects | Increased hunger, water retention, tingling or numbness in extremities, headache; joint pain rare | Injection site reactions, joint pain, fluid retention, tingling, elevated blood sugar |
| Common vial sizes | 2mg, 5mg | 2mg, 5mg, 10mg |
| Mixing math example | 5 mg + 2 mL BAC water = 2,500 mcg/mL, 25 mcg per unit | 5 mg + 2 mL BAC water = 2,500 mcg/mL, 25 mcg per unit |
Key differences
Ipamorelin acts on the ghrelin receptor and is described as a selective growth hormone secretagogue, studied for releasing growth hormone without significantly raising cortisol, prolactin or ACTH. Tesamorelin is a stabilized analog of growth hormone-releasing hormone (GHRH) that acts on the GHRH receptor, the same receptor the body's own GHRH uses.
Tesamorelin is FDA-approved for one specific indication, reducing excess abdominal fat in HIV-associated lipodystrophy, and other uses are off-label. Ipamorelin has no approved product and is sold as a research compound.
Reported side effects overlap in part. Ipamorelin reports include increased hunger, water retention, tingling or numbness in the extremities and headache. Tesamorelin reports include injection site reactions, joint pain, fluid retention, tingling and elevated blood sugar.
What the research covers
Tesamorelin's evidence comes from multiple human clinical trials of visceral fat reduction, which formed the basis of its FDA approval. Ipamorelin's human evidence consists of studies of growth hormone release and how the compound is processed in the body; there is no approved product and formal trial data beyond that is limited.
Sources
- Ipamorelin, the first selective growth hormone secretagogue. Raun K et al. European Journal of Endocrinology, 1998. Preclinical
- Pharmacokinetic-pharmacodynamic modeling of ipamorelin, a growth hormone releasing peptide, in human volunteers. Gobburu JV et al. Pharmaceutical Research, 1999. Human trial
- Metabolic effects of a growth hormone-releasing factor in patients with HIV. Falutz J et al. N Engl J Med, 2007. Human trial
- EGRIFTA (tesamorelin for injection), for subcutaneous use - Prescribing Information. U.S. Food and Drug Administration, 2019. Fda label
Frequently asked questions
What is the difference between ipamorelin and tesamorelin?
Ipamorelin acts on the ghrelin receptor and is studied for selective growth hormone release. Tesamorelin is a GHRH analog that acts on the GHRH receptor and is FDA-approved as Egrifta for HIV-associated lipodystrophy.
Is ipamorelin or tesamorelin FDA-approved?
Tesamorelin is FDA-approved as Egrifta, specifically for HIV-associated lipodystrophy. Ipamorelin is not FDA-approved.
Do ipamorelin and tesamorelin work on the same receptor?
No. Ipamorelin acts on the ghrelin receptor, while tesamorelin acts on the GHRH receptor. Both pathways lead to growth hormone release from the pituitary gland.
Which has more human research, ipamorelin or tesamorelin?
Tesamorelin has more, with multiple human clinical trials that supported its FDA approval. Ipamorelin's human data covers growth hormone release and pharmacokinetics.
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