Tesamorelin and ipamorelin are two peptides that some clinics and users inject together to raise growth hormone. Tesamorelin mimics growth hormone-releasing hormone (GHRH) and is FDA-approved as Egrifta for one narrow use, while ipamorelin mimics ghrelin and is not approved for any use.[1][16] No clinical trial has tested the two together.[21]
This guide covers why people combine them, what human research on similar combinations shows, what each drug’s own evidence says, safety, and legal status. For background on the whole family, see our growth hormone peptides hub.
What are tesamorelin and ipamorelin?
Tesamorelin is a modified version of human GHRH. It is approved to reduce excess abdominal fat in adults with HIV who have lipodystrophy, an abnormal fat distribution linked to HIV treatment.[1] FDA approved the original Egrifta on November 10, 2010.[2] The label says it is not for weight loss, since it has a weight-neutral effect.[1]
Ipamorelin is a five-amino-acid peptide that activates the ghrelin receptor. Novo Nordisk scientists described it in 1998 as the first “selective” growth hormone secretagogue, because in pigs it raised growth hormone without raising the stress hormones ACTH and cortisol.[4] FDA confirms no approved drug contains it.[16]
| Tesamorelin | Ipamorelin | |
|---|---|---|
| Mimics | GHRH[1] | Ghrelin[4] |
| FDA status | Approved (Egrifta) for HIV-related belly fat[1] | Not approved[16] |
| Half-life | About 11 minutes[1] | About 2 hours (IV)[5] |
| Largest published trial | 412 patients, 26 weeks[3] | 114 patients, up to 7 days[6] |
Why people combine a GHRH analog with ipamorelin
The pituitary gland releases growth hormone in response to two main signals: GHRH, and ghrelin acting on its own receptor. The idea behind the stack is to press both buttons at once, with tesamorelin supplying the GHRH signal and ipamorelin the ghrelin signal.[1][4] Users often pick ipamorelin over older ghrelin-type peptides because of its reputation for not raising cortisol, a finding that comes mainly from animal studies.[4][20]
The same reasoning drives the better-known CJC-1295 + ipamorelin stack, which swaps tesamorelin for a different, unapproved GHRH analog. For the older, less selective ghrelin-receptor peptides, see GHRP-2 vs GHRP-6 vs hexarelin.
GHRH plus GHRP: the human research
There is real human research behind the general idea, but none of it used tesamorelin or ipamorelin. Researchers in several countries gave volunteers GHRH (or a short GHRH fragment) together with older ghrelin-type peptides called GHRPs, almost always as a single IV dose:
- USA: in 18 healthy men, low doses of GHRP-6 plus GHRH released growth hormone synergistically, meaning more than the two effects added together.[7]
- Spain: in people with obesity, GHRH plus GHRP-6 produced a “massive” growth hormone discharge, with an average peak about six times higher than GHRH alone.[8]
- Italy: a low dose of hexarelin strongly boosted the response to GHRH in six young men.[10]
- Russia and the UK: a Moscow-London study in eight men found GHRH plus GHRP-2 raised growth hormone more than either alone, but could not show true synergy.[9]
- Serbia and Western Europe: GHRH plus GHRP-6 proved such a strong stimulus that a 250-person multicenter study proposed it as a diagnostic test for adult growth hormone deficiency.[11] In Belgrade, the combination worked as well in people aged 75 to 96 as in younger adults.[12]
Longer use has been studied only in small or special groups:
- Belgium: in critically ill adults, a 21-hour infusion of GHRH plus GHRP-2 doubled growth hormone compared with GHRP-2 alone and raised IGF-1 by a further 40%.[13]
- USA: in 10 older adults with low growth hormone, a tiny dose of GHRP-2 boosted the response to GHRH, and a 30-day continuous infusion of GHRP-2 kept IGF-1 raised.[14]
What each drug’s own evidence shows
Tesamorelin has strong evidence for its approved use. In a phase 3 trial of 412 people with HIV, 2 mg daily for 26 weeks cut deep belly (visceral) fat by 15.2%, versus a 5.0% rise on placebo, and raised IGF-1 by 81%.[3]
Ipamorelin has much less. In healthy men, a single IV infusion caused one burst of growth hormone that peaked about 40 minutes later.[5] In a phase 2 trial of 114 patients after bowel surgery, it did not significantly speed recovery of gut function compared with placebo.[6]
There is also a reason to doubt the pair suits fat loss, tesamorelin’s one proven effect. In mice, ipamorelin increased body fat and food intake through a pathway that did not depend on growth hormone.[15] Whether that happens in people is unknown.
Side effects and safety
No safety data exist for the combination. The evidence for each drug:
Tesamorelin (from the label):[1]
- Most common: joint pain, injection-site redness and itching, pain in the arms or legs, swelling and muscle pain
- Raised blood sugar; the label advises checking glucose before and during treatment
- High IGF-1: 47% of patients on Egrifta for 26 weeks had IGF-1 more than two standard deviations above normal, and the long-term effects of that are unknown
- Not for use in pregnancy or with active cancer
Ipamorelin (IV, after bowel surgery): low potassium (12.5% vs 3.4% on placebo), insomnia (10.7% vs 5.2%) and high blood sugar at discharge (14.3% vs 8.6%) were more common than on placebo. Two patients on ipamorelin died after surgical complications; FDA said it is unclear whether the deaths were drug-related.[16]
Both drugs can raise blood sugar, so stacking them could add to that risk, though this has not been studied.[1][16] FDA’s other concern is product quality: ipamorelin from compounders or online sellers may contain impurities or clumped peptide that can trigger immune reactions.[18]
Dosage: what has been studied
No dose of the combination has been tested.[21]
| Drug | Doses studied in humans |
|---|---|
| Tesamorelin | 2 mg daily in phase 3 trials[3]; Egrifta WR label: 1.28 mg under the skin once daily[1] |
| Ipamorelin | 0.03 mg/kg IV twice daily after surgery[6] |
Egrifta WR and the older Egrifta SV are dosed differently and are not interchangeable.[1] For converting milligrams to syringe units, see our peptide calculator.
Is the tesamorelin and ipamorelin stack legal?
- Tesamorelin: a prescription drug approved for HIV-associated abdominal fat. Use for other purposes is off-label.[1]
- Ipamorelin, outsourcing facilities (503B): FDA lists ipamorelin acetate in category 2, substances that may present significant safety risks, since September 2023; it is not in that category for traditional pharmacies.[18]
- Ipamorelin, traditional pharmacies (503A): in October 2024, FDA’s advisory committee voted 0 to 12, with one abstention, against adding it to the list of substances these pharmacies may use.[17]
- Sport: WADA bans tesamorelin as a GHRH analog and ipamorelin as a growth hormone secretagogue, at all times.[19]
More options and their evidence are on our growth hormone peptides page, including sermorelin and MK-677.
This is general information, not legal advice; rules differ by country and change over time.
