Tesamorelin
A growth-hormone-releasing factor analog with a very unusual status in the peptide world: it is an actual FDA-approved prescription therapy with strong evidence for reducing visceral abdominal fat in a specific medical population.
What It Is
Tesamorelin is a stabilized analog of growth hormone-releasing hormone (GHRH). It stimulates the pituitary to produce and release growth hormone, which in turn increases IGF-1. Unlike most peptides discussed in longevity circles, tesamorelin has an FDA-approved prescription product: EGRIFTA.
The Visceral-Fat Peptide
Tesamorelin’s reputation comes from something unusually concrete: randomized clinical trials showed reductions in visceral adipose tissue (VAT) in adults with HIV-associated lipodystrophy, leading to FDA approval. That has naturally created interest well beyond the approved population.
Its signature use is reducing deep abdominal VAT rather than simply lowering scale weight.
Strong human evidence in approved populationClinical trials reported changes in waist circumference and trunk-fat measures.
Human randomized trialsUsed by some people outside the labeled indication to raise endogenous GH/IGF-1 while retaining pituitary signaling.
Mechanistically established; off-label outcomes varyInterest extends to lean mass, fat distribution and metabolic appearance rather than appetite suppression.
Population-specific human evidenceWhy It Gets Compared With Fat-Loss Drugs — And Why That Is Misleading
Tesamorelin can change abdominal fat distribution without behaving like a GLP-1 drug. It does not primarily work by suppressing appetite, and the FDA label explicitly states that EGRIFTA is not indicated for weight-loss management. Its appeal is more specifically tied to visceral fat and the GH axis.
In pivotal studies, body weight changed very little even while visceral and trunk-fat measures improved — an important clue that tesamorelin is a body-fat-distribution drug in its approved setting, not a conventional scale-weight-loss medication.
GHRH Analog → GH → IGF-1
Tesamorelin binds GHRH receptors on pituitary somatotrophs and increases pulsatile GH secretion. Downstream GH/IGF-1 signaling affects lipolysis and body composition. Because the pituitary remains part of the loop, its physiology differs from directly injecting recombinant HGH.
One Of The Better-Studied Peptides In This Library
Tesamorelin has randomized, placebo-controlled human studies and FDA-reviewed efficacy data for excess abdominal fat in HIV-associated lipodystrophy. That evidence should not automatically be generalized to healthy adults seeking cosmetic fat loss, but it is substantially stronger than the evidence behind most research peptides.
Approved Drug, Narrow Indication
EGRIFTA WR is FDA approved for reducing excess abdominal fat in adults with HIV and lipodystrophy. Important clinical considerations include IGF-1 elevation, glucose intolerance/diabetes risk, fluid-retention effects, injection-site reactions and contraindications related to active malignancy or disruption of the hypothalamic-pituitary axis.
Approved Dosing Is Formulation-Specific
The current U.S. EGRIFTA WR 11.6 mg/vial formulation is labeled at 1.28 mg subcutaneously once daily. EGRIFTA WR and the older EGRIFTA SV formulation are not dose-for-dose interchangeable; each has its own prescribing instructions. The labeled regimen is for the approved HIV-lipodystrophy indication, not general cosmetic fat loss.