Tesamorelin is a synthetic 44-amino-acid analogue of growth hormone-releasing hormone (GHRH). Its N-terminus is modified relative to native GHRH to improve stability and pharmacokinetics. Of the compounds in this catalogue, it has the most substantial human clinical record.
Mechanism
Tesamorelin binds and activates GHRH receptors in the anterior pituitary, prompting synthesis and release of endogenous growth hormone. Growth hormone in turn acts on peripheral tissues including hepatocytes, where it stimulates production of IGF-1, the mediator of most downstream growth hormone effects.
Why a releasing hormone rather than growth hormone itself
This is the interesting part mechanistically. Administering growth hormone directly overrides the body’s control loop. A GHRH analogue works one step upstream, so release stays pulsatile — matching the physiological secretion pattern — and, critically, IGF-1 negative feedback on the pituitary remains intact.
That preserved feedback is what limits runaway growth hormone exposure, and it is the reason GHRH analogues show a different metabolic profile from direct growth hormone administration, particularly with respect to glucose handling.
Clinical record
Tesamorelin has been FDA-approved since 2010 for reduction of excess visceral abdominal fat in adults with HIV-associated lipodystrophy. In a pooled analysis of 806 participants across two Phase III trials, visceral adipose tissue fell by approximately 15.4% versus placebo at 26 weeks.
It has also been studied in nonalcoholic fatty liver disease and in type 2 diabetes, the latter specifically to characterise metabolic safety.
Worth being precise: approval is for one narrow indication in one population. An approved drug is not an approved-for-everything drug, and the material supplied here is not a pharmaceutical product regardless.
Handling
Supplied lyophilised. See our reconstitution protocol for reconstitution technique and diluent selection.
View Tesamorelin and its third-party COA.
Research use only
Isla Longevity supplies this compound for laboratory research use only. It is not approved by the FDA for human or veterinary use and is not for human consumption. This article summarises published research and is not medical guidance.
