Tesamorelin

What Tesamorelin is

Tesamorelin is a synthetic analogue of human growth-hormone-releasing hormone (GHRH). It contains the full 44-amino-acid sequence of GHRH(1–44) with a trans-3-hexenoyl group attached to the N-terminal tyrosine, a modification that slows cleavage by the enzyme dipeptidyl peptidase-4. Developed under the code TH9507, it was approved by the US Food and Drug Administration in 2010 as Egrifta for excess abdominal fat in adults with HIV-associated lipodystrophy, with reformulated versions approved in 2019 and 2025. It is supplied here as a lyophilized (freeze-dried) powder for laboratory research.

What the research examines

Visceral fat in HIV. Two 26-week phase 3 trials (N=412 and N=404) randomised adults with HIV and abdominal fat accumulation to tesamorelin or placebo, measuring visceral adipose tissue by computed tomography, IGF-1 and blood lipids. Both reported a lower visceral fat area in the tesamorelin group at 26 weeks, and their extension phases reported a return towards baseline after the compound was withdrawn.

Liver fat. A 2014 randomised trial in 50 adults with HIV measured liver fat by magnetic resonance spectroscopy over six months, and a 2019 multicentre trial in 61 adults with HIV and non-alcoholic fatty liver disease measured hepatic fat fraction and liver histology over 12 months. Both reported lower hepatic fat in the tesamorelin group than in the placebo group.

Cognition in older adults. A 20-week randomised, placebo-controlled trial in 152 adults, 66 with mild cognitive impairment and 86 cognitively healthy, measured executive function, verbal memory, IGF-1 and glucose regulation. The trial reported differences between groups in composite executive-function scores; a companion study in the same participants measured brain GABA levels by magnetic resonance spectroscopy.

Growth-hormone axis. Pharmacological studies characterised the stability of tesamorelin against dipeptidyl peptidase-4 compared with native GHRH, its activity at the GHRH receptor, and the growth-hormone and IGF-1 responses measured in early clinical pharmacology studies, which form the rationale for the later trials.

Tesamorelin is one of the few research peptides with published phase 3 trials: randomised, placebo-controlled studies in adults with HIV and one trial in older adults. The same molecule is an approved medicine in the United States, marketed as Egrifta (approved 2010), with reformulations Egrifta SV (2019) and Egrifta WR (2025). The research-grade material sold here is not a medicine, and this page makes no claims about effects in humans.

Selected literature

• Falutz J, et al. New England Journal of Medicine, 2007, phase 3 trial, N=412, 26 weeks plus extension. doi:10.1056/NEJMoa072375
• Stanley TL, et al. JAMA, 2014, randomised trial, N=50, six months. doi:10.1001/jama.2014.8334
• Stanley TL, et al. The Lancet HIV, 2019, randomised trial, N=61, 12 months. doi:10.1016/S2352-3018(19)30338-8
• Baker LD, et al. Archives of Neurology, 2012, randomised trial, N=152, 20 weeks. doi:10.1001/archneurol.2012.1970

Every reference is listed with its DOI in the research library.

Handling in the laboratory

Store sealed at 2–8 °C for routine use or frozen for long-term storage, protected from light and moisture. Let the vial reach room temperature before opening. See Storage and handling of lyophilized research peptides.