What Is Tesamorelin? GHRH Analogue Mechanism & UK Status

Tesamorelin is a synthetic analogue of human growth hormone-releasing hormone (GHRH). It consists of the full 44-amino-acid GHRH sequence with a trans-3-hexenoic acid group attached to the N-terminus — a modification that resists enzymatic (DPP-IV) degradation and extends the peptide's stability while preserving activity at the GHRH receptor. It was developed by Theratechnologies.

Research use only. Material supplied as a research peptide is intended for in-vitro laboratory use. It is not a medicine and is not for human or veterinary consumption, administration, or therapeutic use.

Tesamorelin binds the GHRH receptor on the anterior pituitary and stimulates release of the body's own growth hormone (GH), which in turn raises insulin-like growth factor 1 (IGF-1). Its short half-life (approximately 26–38 minutes) means it produces a discrete GH pulse rather than continuous signalling — a feature studied for preserving the natural pulsatile GH rhythm. In clinical research this GH-mediated effect was associated with preferential reduction of visceral (deep abdominal) adipose tissue rather than subcutaneous fat.

Tesamorelin is the only GHRH analogue to hold a regulatory approval. In pivotal Phase 3 trials in HIV-associated lipodystrophy (Falutz et al., New England Journal of Medicine, 2007), it reduced visceral adipose tissue by approximately 15–18% over 26 weeks, with improvements in triglycerides and, in later studies, liver fat. These results pertain to a specific patient population studied under medical supervision and do not constitute medical advice or apply to research-grade material.

Tesamorelin is FDA-approved in the United States (as Egrifta, 2010; Egrifta SV, 2019; Egrifta WR, 2025) for one narrow indication: reduction of excess abdominal fat in HIV-associated lipodystrophy. It has no UK marketing authorisation — in the UK it is an unlicensed medicine that could only be supplied to a patient on a named-patient basis under full prescriber responsibility. It is also a prohibited substance in sport under World Anti-Doping Agency (WADA) rules. Research-grade tesamorelin is supplied strictly for laboratory research use only.

As a lyophilised peptide, tesamorelin is kept frozen and reconstituted with bacteriostatic water for in-vitro work — see our reconstitution guide and storage guide. Identity and purity should be verified against a batch-matched Certificate of Analysis (COA) with HPLC and mass-spectrometry data.

Tesamorelin is the full GHRH(1-44) sequence with a stabilising modification. Other GH-axis research peptides such as CJC-1295 and ipamorelin act on related but distinct targets — see CJC-1295 vs Ipamorelin. It is mechanistically unrelated to incretin agonists such as retatrutide. View tesamorelin product details and COA.

Tesamorelin is supplied strictly for in-vitro laboratory research use only. The peer-reviewed references below are provided for research context and do not imply that the compound is safe or effective for use in humans.

1. Falutz J, et al. Metabolic effects of a growth hormone-releasing factor in patients with HIV. N Engl J Med. 2007;357(23):2359-2370. View source