# Tesamorelin: The Visceral-Fat Record, Read Straight > Tesamorelin cut visceral fat by 15.2% in the pivotal HIV-lipodystrophy trial (n=412). A terminal-style digest of what the trials measured, what is FDA-approved, and what stays off-label. A systematic readout of the published tesamorelin literature: the measured visceral-fat, IGF-1, and hepatic-fat numbers logged and cited, with the HIV-only scope and the reversal-on-discontinuation printed beside every returned value. ## The short version Tesamorelin is a lab-made copy of GHRH (the brain's own "make growth hormone" signal), tweaked so the body breaks it down more slowly. It nudges the pituitary gland to release the body's own growth hormone in natural bursts, which raises IGF-1 (a growth signal the liver makes when growth hormone rises) and burns off visceral fat — the deep belly fat packed around the organs. In the largest trial, of 412 people with HIV-related fat buildup, that visceral fat dropped 15.2% while placebo rose 5.0% [1]. One catch the studies are clear about: it is FDA-approved for that HIV use only, and the fat comes back when you stop [2][6]. ## What the tesamorelin literature has actually demonstrated Tesamorelin is a synthetic 44-amino-acid analogue of growth hormone-releasing hormone — GHRH(1-44) — carrying a trans-3-hexenoic acid group on its N-terminus that resists DPP-IV (dipeptidyl peptidase-IV, the protease that rapidly chews up the body's natural GHRH) [1]. By surviving longer, it stimulates the pituitary's own pulsatile growth-hormone (GH) secretion and raises liver-produced IGF-1, and the two together drive lipolysis — the breakdown of stored fat — preferentially in visceral adipose tissue [4]. The headline finding is reproducible. In the pivotal 26-week Phase 3 randomized controlled trial of 412 HIV patients with abdominal fat accumulation, tesamorelin 2 mg/day reduced visceral adipose tissue (VAT) by 15.2% while placebo rose 5.0%; triglycerides fell 50 mg/dL and IGF-1 rose 81.0% [1]. Over the full 52-week program, the VAT reduction was sustained at -18% versus baseline [2]. A 2026 meta-analysis of five RCTs pooled the effect at -27.71 cm² of visceral fat, -1.18 kg of trunk fat, and +1.42 kg of lean mass [13]. What the studies are equally clear about is scope. Every pivotal efficacy trial enrolled HIV-positive adults on antiretroviral therapy [1][2][6]; the visceral fat reaccumulated when dosing stopped [2][6]; and FDA approval covers exactly one indication. The [side effects and contraindications](/faq) and whether [is tesamorelin FDA approved](/faq) are documented in full on the FAQ. This page logs the established findings; their boundaries are logged beside them. ## Tesamorelin as a peptide: a stabilized GHRH(1-44) analogue As a peptide, tesamorelin is the full-length human GHRH sequence — all 44 amino acids — rather than a truncated fragment. Its only structural departure from native GHRH(1-44) is the trans-3-hexenoic acid group conjugated to the N-terminus, an unsaturated fatty-acid cap [1]. That single modification is what makes the tesamorelin peptide pharmacologically useful: it blocks DPP-IV cleavage at the second amino-acid position, which is how the body inactivates natural GHRH within minutes, extending the molecule's window of activity at the GHRH receptor [4]. The free base carries the empirical formula C221H366N72O67S, a molecular weight of 5135.9 Da, and CAS number 218949-48-5; it is supplied clinically as the acetate salt [1]. Mechanistically it is a GHRH-receptor agonist, not a growth hormone and not a ghrelin-mimetic secretagogue — a distinction that shapes the whole [tesamorelin vs sermorelin](/vs-sermorelin) comparison, where the difference is full-length GHRH(1-44) versus the truncated GHRH(1-29) sequence. ## Studied benefits of tesamorelin The studied benefits of tesamorelin are specific and measured, not general. In the HIV-lipodystrophy population they cluster around visceral fat and its metabolic consequences. The pivotal trial recorded the 15.2% VAT reduction alongside a 50 mg/dL triglyceride decrease [1]. A pooled analysis of two Phase 3 RCTs (543 tesamorelin vs 263 placebo) found the odds of reducing VAT below 140 cm² were 3.9-fold greater with tesamorelin (95% CI 2.03–7.44) [10]. The benefit is concentrated in responders: HIV patients achieving at least 8% VAT reduction showed significantly greater triglyceride reductions and a more favorable metabolic profile than non-responders, tying the metabolic gain to the degree of visceral-fat loss [7]. A separate analysis found the inflammatory-marker improvements — reduced tissue plasminogen activator antigen, increased adiponectin — tracked the VAT reduction rather than a direct GH effect, identifying visceral fat as the mediating mechanism [8]. Tesamorelin also improved fat *quality*: over 26 weeks it raised visceral and subcutaneous fat density on CT (VAT +6.2 vs +0.3 HU placebo; SAT +4.0 vs +0.3 HU; both P<0.0001), an adipocyte-quality gain independent of changes in fat quantity [9]. These are the documented effects in the studied population — not a projection for anyone outside it. ## Is tesamorelin FDA approved? Yes — but only for one indication, and the scope matters. Tesamorelin was approved in the United States in 2010 (NDA 022505) to reduce excess abdominal fat in HIV-infected patients with antiretroviral-related lipodystrophy [5]. That is the entire labeled use. Every other application — general or cosmetic weight loss, anti-aging, bodybuilding, non-HIV fat loss, GH "optimization" — is off-label and not an FDA-approved indication. The NIH LiverTox monograph, summarizing the drug-safety record, assigns tesamorelin a likelihood score of E (unlikely cause of clinically apparent liver injury), noting no reported attributable liver-injury cases [5]. Tesamorelin is also prohibited in sport under the WADA Prohibited List category S2 (peptide hormones, growth factors), in- and out-of-competition. A 2026 sports-medicine primer noted it as approved only for HIV-associated lipodystrophy with no orthopaedic evidence base [15]. The pages here concern research-grade tesamorelin supplied for laboratory study — not the approved finished drug, and not a medicine to self-administer. --- A terminal trace of the peer-reviewed tesamorelin record — every visceral-fat and IGF-1 figure returned green and sourced, the HIV-lipodystrophy-only scope and the reverts-when-you-stop caveat printed beside the value, never behind it; no clinic at this prompt and nothing here dosed, dispensed, or sold.