# Tesamorelin: FDA-Approved GHRH Analogue — Research Digest > Tesamorelin is a 44-amino-acid GHRH analogue that reduced visceral fat by 15–18% in Phase III trials. An independent digest of the clinical evidence, cited to primary sources. ## What the Tesamorelin Literature Has Established Tesamorelin is a synthetic 44-amino-acid analogue of human growth hormone-releasing hormone (GHRH), modified at the N-terminus with a trans-3-hexenoic acid group that confers resistance to dipeptidyl peptidase-IV (DPP-IV) degradation. The FDA approved the compound in 2010 under NDA 022505 for the reduction of excess abdominal fat in HIV-infected adults with lipodystrophy. [1] Across two pivotal Phase III randomized controlled trials and a 52-week extension study, 2 mg/day subcutaneous tesamorelin produced a 15.2–18% reduction in visceral adipose tissue (VAT) area compared to placebo. [1][2][3] Triglycerides decreased by approximately 50 mg/dL and adiponectin increased, while fasting glucose remained metabolically stable. [4] Two dedicated secondary trials extended these findings to the liver. A 6-month randomized trial (n=61) found tesamorelin reduced hepatic fat fraction by 2.0 percentage points versus a 0.9 point increase in the placebo group (P=0.003). [5] A 12-month Phase 2 double-blind trial in HIV-infected patients with non-alcoholic fatty liver disease documented a 37% relative reduction in liver fat fraction, with 35% of tesamorelin recipients versus only 4% of placebo recipients achieving a hepatic fat fraction below 5%. [6] A controlled trial in adults aged 55–87 years found that 20 weeks of tesamorelin at 1 mg/day improved executive function (P=0.005) and raised IGF-1 by 117% into the physiological young-adult range. [7] A 2026 meta-analysis pooling five randomized controlled trials quantified the body-composition benefit at −27.71 cm² VAT, −1.18 kg trunk fat, −4.28% hepatic fat, and +1.42 kg lean body mass, without perturbation of glucose or serious adverse events. [16] ## What Is the Tesamorelin Peptide? Tesamorelin — also designated TH9507 — is the full 44-amino-acid sequence of human GHRH(1-44)-NH2 with a single structural modification: a trans-3-hexenoic acid group added to the N-terminus. This modification blocks cleavage by DPP-IV, extending the compound's plasma half-life from approximately 7 minutes (native GHRH) to 26–38 minutes (tesamorelin) while preserving full agonist activity at the GHRH receptor (GHRH-R). [9] Tesamorelin is classified as a peptide hormone analogue, not a steroidal compound. It stimulates endogenous, pulsatile GH secretion rather than supplying GH exogenously. A population pharmacokinetic analysis confirmed a plasma clearance of approximately 1,060 L/h and a volume of distribution of approximately 200 L; absorption fraction increased 13.1% from day 1 to day 14, consistent with a cumulative receptor-priming effect. [9] ## How Tesamorelin Works: The GHRH Receptor Pathway Tesamorelin binds with high affinity to GHRH receptors (Gs-coupled GPCRs) on somatotroph cells in the anterior pituitary. Receptor activation initiates the adenylyl cyclase/cAMP/PKA cascade, triggering pulsatile GH synthesis and release. Elevated GH then drives hepatic synthesis of insulin-like growth factor-1 (IGF-1) via JAK2/STAT5 signaling. [1] The downstream lipolytic effect is selective for visceral adipose depots. IGF-1 activates hormone-sensitive lipase in visceral adipocytes, mobilizing stored triglycerides and reducing VAT area without meaningfully changing subcutaneous fat or BMI. [1][3] For the liver, tesamorelin appears to operate through a distinct secondary pathway. Hepatic transcriptomic analysis in HIV-associated NAFLD patients found significant upregulation of oxidative phosphorylation gene sets and downregulation of inflammatory and fibrosis-related gene sets. [12] ## Tesamorelin FDA Approval and Regulatory History Tesamorelin FDA approval was granted on November 10, 2010, under NDA 022505 (Egrifta, 1 mg/vial formulation), based on two Phase III randomized controlled trials (LIPO-010 and LIPO-011) in HIV-infected adults with lipodystrophy-associated abdominal fat accumulation. [1][2] A higher-concentration formulation (Egrifta SV, 2 mg/vial) was approved under the same NDA in 2019. Tesamorelin is not approved for use outside the HIV-lipodystrophy indication; all other investigational applications remain off-label research. Tesamorelin falls under the WADA Prohibited List (S2 category: peptide hormones, growth factors, and related substances) when used in sporting contexts. ## Tesamorelin Research Applications and Safety Overview The published research record covers four primary areas: (1) visceral fat reduction in HIV-associated lipodystrophy; (2) hepatic steatosis and NAFLD; (3) cognitive function in aging and mild cognitive impairment; and (4) body composition and metabolic parameters in non-HIV populations including type 2 diabetes. The most common adverse events in clinical trials were injection-site reactions, arthralgias, myalgias, and mild fluid retention. [1][2] A 12-week study in type 2 diabetes patients found no significant change in fasting glucose or HbA1c, while total and non-HDL cholesterol decreased significantly in the 2 mg group. [11] ## References [1] Falutz J, et al. Metabolic effects of a growth hormone-releasing factor in patients with HIV. N Engl J Med. 2007;357(23):2359-70. https://pubmed.ncbi.nlm.nih.gov/18057338/ [2] Falutz J, et al. Long-term safety and effects of tesamorelin in HIV patients with abdominal fat accumulation. AIDS. 2008;22(14):1719-28. https://pubmed.ncbi.nlm.nih.gov/18690162/ [3] Falutz J, et al. Effects of tesamorelin in HIV-infected patients with abdominal fat accumulation. J Acquir Immune Defic Syndr. 2010;53(3):311-22. https://pubmed.ncbi.nlm.nih.gov/20101189/ [4] Stanley TL, et al. Reduction in Visceral Adiposity Is Associated With an Improved Metabolic Profile. Clin Infect Dis. 2012;54(11):1642-1651. https://pubmed.ncbi.nlm.nih.gov/22495074/ [5] Stanley TL, et al. Effect of Tesamorelin on Liver Fat and Visceral Fat. JAMA. 2014;312(4):380-389. https://pubmed.ncbi.nlm.nih.gov/25038357/ [6] Stanley TL, et al. Effects of tesamorelin on non-alcoholic fatty liver disease in HIV. Lancet HIV. 2019;6(12):e821-e830. https://pubmed.ncbi.nlm.nih.gov/31611038/ [7] Baker LD, et al. Effects of growth hormone-releasing hormone on cognitive function. Arch Neurol. 2012;69(11):1420-9. https://pubmed.ncbi.nlm.nih.gov/22869065/ [9] González-Sales M, et al. Population pharmacokinetic analysis of tesamorelin. Clin Pharmacokinet. 2015;54(3):285-94. https://pubmed.ncbi.nlm.nih.gov/25358450/ [11] Clemmons DR, et al. Safety and metabolic effects of tesamorelin in patients with type 2 diabetes. PLoS One. 2017;12(6). https://pubmed.ncbi.nlm.nih.gov/28617838/ [12] Fourman LT, et al. Effects of tesamorelin on hepatic transcriptomic signatures in HIV-associated NAFLD. JCI Insight. 2020;5(16). https://pubmed.ncbi.nlm.nih.gov/32701508/ [16] Rousakis A, et al. Body composition, hepatic fat, metabolic, and safety outcomes of Tesamorelin — meta-analysis. Obes Res Clin Pract. 2026;20(1):2-12. https://pubmed.ncbi.nlm.nih.gov/41545261/ --- A peer-reviewed field record of the tesamorelin literature — FDA approvals, Phase III trials, and pharmacokinetics indexed here, not prescribed here.