Last reviewed May 22, 2026·Editorial Board
Tesamorelin (Egrifta)
Also known as TH9507, Egrifta, Egrifta SV, Egrifta WR
Tesamorelin is a stabilized synthetic analog of growth hormone-releasing hormone (GHRH 1-44) with an N-terminal hexenoyl modification that resists enzymatic cleavage. It is the only GHRH-class peptide with current FDA approval as a finished drug product, indicated for the reduction of excess abdominal fat in HIV-infected patients with lipodystrophy.[1]
What tesamorelin is
Tesamorelin (developmental code TH9507) is a 44-amino-acid GHRH analog with a hexenoyl group attached to the N-terminus. Native GHRH is rapidly degraded by dipeptidyl peptidase-IV (DPP-IV); the hexenoyl modification blocks this cleavage and extends the functional half-life of the molecule, while preserving binding to the pituitary GHRH receptor.[2]
The result is a peptide that produces a more sustained GH-releasing signal than native GHRH or sermorelin (~26 minute plasma half-life vs. ~11 minutes for sermorelin), while still acting upstream through the pituitary's own secretory machinery. As with sermorelin, GH release remains under normal feedback regulation — IGF-1 elevation suppresses further GH secretion — which differentiates this class from exogenous somatropin.
Tesamorelin holds the distinction of being the only GHRH-class peptide that completed pivotal trials and received FDA approval that remains active in 2026. It was approved in November 2010 under the brand name Egrifta. A more concentrated formulation, Egrifta SV (F4), was subsequently approved. A further reformulation, Egrifta WR (F8 — 8× concentrated, weekly reconstitution instead of daily), was approved March 25, 2025.[3]
Mechanism of action
Tesamorelin binds the GHRH receptor on anterior pituitary somatotrophs (a Gs-coupled GPCR), elevating intracellular cAMP and triggering pulsatile growth hormone release. Released GH acts at the liver and peripheral tissues to drive IGF-1 production and engage GH-dependent metabolic pathways including lipolysis in visceral adipose depots.[2]
The HIV-lipodystrophy use case rests on two mechanistic observations: (1) HIV-associated lipodystrophy involves disproportionate accumulation of visceral adipose tissue (VAT), and (2) GH preferentially mobilizes visceral fat. Restoring physiologic GH pulse amplitude via GHRH stimulation reduces VAT without the supraphysiologic GH exposures associated with direct somatropin administration.
Human evidence
Tesamorelin has the strongest human dataset of any peptide in this database. The Phase 3 program enrolled ~800 patients across two multicenter trials with safety extension data, supporting the 2010 FDA approval. Subsequent investigator-initiated work has examined NAFLD (non-alcoholic fatty liver disease) in HIV.
Marketed claims vs. published evidence
The published evidence base for tesamorelin is narrow but strong: it works in HIV-associated lipodystrophy (FDA-approved indication) and shows real signal in HIV-associated NAFLD (off-label). The dataset does not extend to general-population fat loss, anti-aging applications, or NAFLD outside HIV.
Regulatory status
Tesamorelin is the only growth-hormone-axis peptide on this site with active FDA approval as a finished drug product:
- Egrifta — approved November 10, 2010 for reduction of excess abdominal fat in HIV-infected patients with lipodystrophy.[1]
- Egrifta SV — F4 reformulation approved earlier than Egrifta WR; reduced injection volume.
- Egrifta WR — F8 reformulation (8× more concentrated, weekly reconstitution) approved March 25, 2025.[3]
Because a finished FDA-approved product is commercially available, the compounding question is largely moot for tesamorelin. Off-label use should be of the approved branded product rather than a compounded version; this is both a quality and a liability question.
Tesamorelin is on the WADA Prohibited List (S2) as a GH secretagogue.[6]
Safety considerations
The Phase 3 safety profile included injection-site reactions, mild glucose tolerance changes (HbA1c effects generally small but present), occasional fluid retention/arthralgia consistent with GH-axis activation, and IGF-1 elevation typically remaining within the normal range.[4]
The most clinically relevant ongoing safety question is long-term cancer risk from sustained IGF-1 elevation. The Phase 3 trials were not powered for malignancy endpoints. Tesamorelin is contraindicated in patients with active malignancy, and the prescribing information instructs discontinuation if pituitary disease or active neoplasia develop.
Dosing is not addressed on this page. Dosing decisions belong with a licensed prescriber working from the FDA prescribing information for the specific formulation (Egrifta, Egrifta SV, or Egrifta WR).
Frequently asked questions
Related peptides
Citations
- U.S. Food and Drug Administration. EGRIFTA (tesamorelin for injection) — Approval for reduction of excess abdominal fat in HIV-infected patients with lipodystrophy. FDA Drug Approval Package, NDA 022505. 2010. ↗ Source fda
- Falutz J, Allas S, Blot K, et al. Metabolic effects of a growth hormone-releasing factor in patients with HIV. New England Journal of Medicine. 2007. PMID 18057338
- Theratechnologies / U.S. Food and Drug Administration. EGRIFTA WR (tesamorelin F8 formulation) — supplemental BLA approval, increased concentration, weekly reconstitution. Theratechnologies press release / FDA action. 2025. ↗ Source fda
- Falutz J, Mamputu JC, Potvin D, et al. Effects of tesamorelin (TH9507), a growth hormone-releasing factor analog, in HIV-infected patients with excess abdominal fat: a pooled analysis of two multicenter, double-blind placebo-controlled phase 3 trials with safety extension data. Journal of Clinical Endocrinology and Metabolism. 2010. PMID 20554713
- Stanley TL, Fourman LT, Feldpausch MN, et al. Effects of tesamorelin on non-alcoholic fatty liver disease in HIV: a randomised, double-blind, multicentre trial. The Lancet HIV. 2019. ↗ Source DOI: 10.1016/S2352-3018(19)30338-8
- World Anti-Doping Agency. The 2026 Prohibited List — S2 Peptide Hormones, Growth Factors, Related Substances and Mimetics. wada-ama.org. 2026. ↗ Source wada
- 2026-05-22Initial page. Pivotal Phase 3 (NEJM 2007), pooled analysis (JCEM 2010), HIV-NAFLD (Lancet HIV 2019), 2010 FDA approval, and March 2025 Egrifta WR F8 reformulation noted.