# Tesamorelin: The GHRH(1-44) Research Record, Filed as Typed Fields > tesamorelin is a synthetic GHRH(1-44) analogue FDA-approved only for HIV-associated lipodystrophy. The mechanism, the visceral-fat trials, and the labeled contraindications, each cited to source. A typed digest of the published evidence — the receptor mechanism, the visceral-fat numbers, the pharmacokinetics, and the labeled contraindications — with the FDA scope (HIV-associated lipodystrophy only) surfaced before the figures. ## The short version Tesamorelin is a lab-made copy of GHRH (the brain's own "make growth hormone" signal), built to last longer in the blood. It nudges the pituitary 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 deep belly fat. The U.S. FDA approved it in 2010 for one job only: shrinking excess visceral fat (the deep belly fat packed around the organs) in people with HIV-associated lipodystrophy. Every other use is off-label. This site reads that record straight and cites each number to its study. ## What the tesamorelin record actually establishes Tesamorelin is a synthetic 44-amino-acid analogue of human growth hormone-releasing hormone, GHRH(1-44), carrying an N-terminal trans-3-hexenoic acid group that blocks the enzyme (DPP-IV) which normally chews up natural GHRH within minutes [10]. That single modification is the whole design: it lets the molecule survive long enough to act, so it amplifies the body's own pulsatile growth-hormone (GH) rhythm rather than supplying GH from outside. The headline efficacy number comes from a pivotal 26-week Phase 3 trial of 412 HIV patients with abdominal fat accumulation: tesamorelin 2 mg/day reduced [the visceral-fat research](/research) — visceral adipose tissue, the deep fat around the organs — by 15.2%, while placebo *increased* it by 5.0%; triglycerides fell by 50 mg/dL and IGF-1 rose 81.0% [5]. A 52-week program sustained the visceral-fat reduction at -18% [6]. A 2026 meta-analysis of five randomized trials pooled a visceral-fat reduction of -27.71 cm2 and a hepatic-fat-fraction reduction of -4.28%, with no serious adverse events [15]. Those are large, reproduced effects — but they were all measured in one population. This is a structured research record, not a sales page: where the evidence stops, the record says so, and the [labeled contraindications](/side-effects) lead rather than trail the numbers. ## Tesamorelin as a synthetic GHRH(1-44) peptide The tesamorelin peptide is the full-length GHRH(1-44) sequence — all 44 residues of the natural hormone — rather than a shortened fragment [12]. Native GHRH is rapidly inactivated by dipeptidyl peptidase-IV (DPP-IV), a protease that clips peptides at the N-terminus; tesamorelin's trans-3-hexenoic acid cap sits exactly where DPP-IV would cut, so the analogue resists that deactivation and stays active in plasma far longer than native GHRH [10]. Chemically it is filed as tesamorelin acetate: empirical formula C221H366N72O67S, molecular weight 5135.9 Da, CAS 218949-48-5, supplied as a lyophilized powder requiring reconstitution [1]. It is a growth hormone-releasing hormone receptor agonist (ATC code H01AC06), and it is not endogenous — it is a stabilized copy of an endogenous hormone, not the hormone itself. ## What tesamorelin was studied and approved for What tesamorelin was studied and approved for is narrow and specific: reducing excess visceral abdominal fat in HIV-infected adults whose antiretroviral therapy has driven fat redistribution (HIV-associated lipodystrophy). That is the only indication the U.S. FDA has cleared, and every pivotal efficacy trial was run in HIV-positive adults on antiretroviral therapy [5][6]. Research endpoints beyond that indication exist — hepatic fat in HIV-associated fatty liver disease [7], a mechanistic study in healthy men [8], a cognition trial in older adults — but none has been approved, and no large general-population fat-loss trial has been completed. Any use outside HIV-associated lipodystrophy is off-label and investigational. Research-grade tesamorelin supplied for laboratory work is not the approved finished drug product and is not characterized for human self-administration. ## Is tesamorelin FDA approved? Yes, but narrowly. Tesamorelin was approved in the United States in 2010 under NDA 022505 to reduce excess abdominal fat in HIV-infected patients with antiretroviral-related lipodystrophy [4]. It is genuinely an approved prescription drug for that indication — not an unapproved compound — but the approval does not extend to any non-HIV, cosmetic, anti-aging, or performance use, all of which are off-label. Tesamorelin is also prohibited in sport under the World Anti-Doping Agency Prohibited List, category S2 (peptide hormones, growth factors), in- and out-of-competition. ## What is tesamorelin? Tesamorelin is a synthetic 44-amino-acid analogue of human growth hormone-releasing hormone, GHRH(1-44), with an N-terminal trans-3-hexenoic acid group that resists DPP-IV cleavage [10]. It stimulates pulsatile endogenous growth hormone and raises IGF-1 [8]. It is FDA-approved only to reduce excess abdominal fat in HIV-associated lipodystrophy [4]. ## What does tesamorelin do? It amplifies the body's own pulsatile growth-hormone rhythm, raising IGF-1 and promoting lipolysis — the breakdown of stored fat — preferentially in visceral adipose tissue [5]. In the pivotal HIV trial that translated to a 15.2% reduction in visceral fat versus a 5.0% increase on placebo [5]. The approval is limited to HIV-associated lipodystrophy. ## How does tesamorelin work? It binds the GHRH receptor (a Gs-coupled receptor) on pituitary somatotroph cells, raising cAMP/PKA signaling and stimulating growth-hormone synthesis and pulsatile secretion; the released GH then drives hepatic IGF-1 production and visceral-fat lipolysis [5][8]. Because it works through the body's own GH machinery, its profile differs from injecting GH directly. The [mechanism of action](/research) is detailed on the research page. --- The tesamorelin literature read as a validated record — every figure typed to its field and carried back to its study, the FDA scope (HIV-associated lipodystrophy only), the labeled contraindications, and the off-label edge surfaced as the record's leading status; a digest that flags before it reports, never a clinic, a vendor, or a prescription.