What Is Tesamorelin?
Tesamorelin (TransCon hGH, trade name Egrifta) is a synthetic analogue of endogenous GHRH consisting of the full 44 amino acid sequence of GHRH with a trans-3-hexenoic acid group attached at the N-terminus. This modification enhances stability and prolongs the half-life compared to native GHRH.
In 2010, the FDA approved tesamorelin for the treatment of excess visceral adipose tissue (VAT) in HIV-positive adults receiving antiretroviral therapy — a condition causing pronounced central fat accumulation (lipodystrophy) as a side effect of protease inhibitors.
Mechanism of Action
Like other GHRH analogues, tesamorelin binds the pituitary GHRH receptor, stimulating pulsatile GH secretion. The GH increase is self-regulating via normal negative feedback through IGF-1, which is important for safety.
Clinical Evidence
- Phase III LPHT trials (n=816): Tesamorelin produced a 15–18% reduction in VAT versus placebo after 26 weeks in HIV lipodystrophy
- Liver fat: Significant reductions in hepatic triglyceride content in HIV-associated MASLD
- Lipid profile: Reductions in triglycerides and non-HDL cholesterol observed
- IGF-1 elevation: Tesamorelin raises IGF-1 levels, which is monitored in ongoing research for safety
Research Beyond HIV
Given its established mechanism and safety data, tesamorelin research has expanded to:
- Non-HIV lipodystrophy and metabolic syndrome
- Cognitive decline: IGF-1 mediated neuroprotection in mild cognitive impairment (MCI) — Phase II data suggesting improvements in working memory
- Age-related GH decline (AGHD research)
Related compounds: Sermorelin, CJC-1295, Semaglutide.