Compound profile
Tesamorelin
Stronger clinical signalAlso known as: Egrifta · GHRH analogue
A synthetic GHRH analogue with an approved indication for reducing excess abdominal fat in specific HIV-associated lipodystrophy contexts, often referenced when discussing visceral fat and GH axis research.
Overview
Tesamorelin is a synthetic analogue of growth hormone-releasing hormone (GHRH), engineered from the native 44-amino-acid human GHRH sequence with a chemical modification at the N-terminus that protects it from rapid enzymatic breakdown. It was developed by Theratechnologies and is one of the few peptides in this category with a genuine FDA approval behind it.
The FDA approved tesamorelin, sold as Egrifta, in November 2010 for a specific and fairly narrow indication: reducing excess visceral abdominal fat in people with HIV-associated lipodystrophy, a fat redistribution syndrome linked to HIV infection and its treatment. Theratechnologies later introduced reformulated versions, Egrifta SV and then Egrifta WR, that reduced the injection volume and simplified reconstitution, with an updated formulation (referred to as tesamorelin F8) approved in 2025.
Because of its approval, tesamorelin has a real clinical trial and post-marketing safety record, unlike most research-only GH secretagogues. That said, its approval is specific to a defined patient population with a defined metabolic condition, and the visceral fat reduction it produces in that context does not automatically generalize to broader fitness or aesthetic fat-loss use in people without HIV-associated lipodystrophy, even though it gets referenced in that context in online GH-axis discussions.
Mechanism (plain language)
Stimulates endogenous GH secretion via GHRH receptors, increasing IGF-1 and influencing lipolysis patterns studied in indicated populations.
How it works
Tesamorelin binds to and activates the GHRH receptor on pituitary cells, the same receptor engaged by the body's own GHRH, stimulating pulsatile release of growth hormone. The modification at the N-terminus of the peptide protects it from the enzymes that would otherwise break down native GHRH within minutes, extending its effective activity enough to support once-daily dosing.
The resulting increase in GH and downstream IGF-1 is associated with lipolysis, the breakdown of stored fat, with trial data specifically showing a preferential effect on visceral adipose tissue, the metabolically active fat stored around abdominal organs, more than on subcutaneous fat. This is consistent with GH's known role in fat metabolism generally, but tesamorelin's approved indication is specifically tied to the abnormal fat redistribution pattern seen in HIV-associated lipodystrophy, and the trials supporting its approval were conducted in that population rather than in the general public seeking cosmetic or athletic fat loss.
What research suggests
Randomized trials support visceral adipose reductions in labeled populations. Extrapolation to general fitness or aesthetic fat loss should be treated cautiously.
Reported benefits
What studies, case reports, and the research literature describe, not guaranteed outcomes. The trials behind these findings are in the studies below.
Visceral fat reduction
Randomized, placebo-controlled trials in people with HIV-associated lipodystrophy reported significant reductions in visceral adipose tissue, the pivotal evidence behind the FDA approval.
Liver fat reduction
A dedicated trial in the same population reported reductions in visceral and liver fat, an area of particular relevance given elevated hepatic fat risk in HIV-associated lipodystrophy.
GH and IGF-1 restoration
Trials report tesamorelin restores more normal GH and IGF-1 levels in the indicated population, consistent with its mechanism as a GHRH receptor agonist.
Uncertainties & risks
Approved drug with specific indication, not a general fat-loss peptide guide. IGF-1 elevation, glucose effects, and injection-site reactions are documented. Off-label athletic use lacks strong outcome data.
Tesamorelin's approval is narrow and disease-specific, and that context matters when it comes up in general fitness or longevity conversations. The trials that support its use were conducted in people with HIV-associated lipodystrophy, and extrapolating those visceral-fat results to general aesthetic or athletic fat loss in people without that condition is not something the approved trials were designed to test. The most closely monitored risk is IGF-1 elevation, since the effects of prolonged elevated IGF-1 are not fully characterized, and the label calls for monitoring IGF-1 levels during treatment. Injection-site reactions are common and can include redness, swelling, and rarely more serious skin reactions. Tesamorelin is contraindicated in pregnancy and in people with a history of pituitary tumor, pituitary surgery, or head injury involving that region, and hypersensitivity to the drug or its excipients rules it out as well. Because it is a prescription medicine tied to a specific label rather than a general-purpose research compound, use outside its indicated population and outside medical supervision falls outside what the approval and safety data actually cover.
STACKD study summaries
Start with our in-house roundups, plain-language synthesis of the research, with primary sources cited at the bottom of each.
Primary sources
Secondary citations for verification. Prefer the STACKD summary above for context before opening these.