Tesamorelin.

Tesamorelin is an approved drug in the growth-hormone secretagogues.

Stimulating the pituitary's GHRH receptor to release growth hormone.

It draws interest for growth-hormone secretagogues and is prescribed for its approved indication(s).

Yes for its approved use(s), with caveats — strong human trial evidence underpins the label, but broader wellness/longevity claims are not proven.

What it is

Tesamorelin is a synthetic 44-amino-acid analog of human growth hormone-releasing hormone (GHRH/GRF 1-44), stabilized by a trans-3-hexenoic acid group attached to its N-terminus. It is one of the few research peptides in its class that holds full FDA approval, marketed as Egrifta (and the reformulated Egrifta SV / Egrifta WR) by Theratechnologies for a narrow, specific indication. Originally designated TH9507, it is a secretagogue rather than a hormone itself.

How it works

Tesamorelin binds the GHRH receptor on the anterior pituitary, stimulating the synthesis and pulsatile release of the body's own growth hormone (GH), which in turn raises hepatic and circulating insulin-like growth factor-1 (IGF-1). Because it works upstream by amplifying endogenous GH secretion, it largely preserves physiological feedback and pulsatility, unlike direct exogenous GH administration. The N-terminal hexenoyl modification confers resistance to degradation (including by dipeptidyl peptidase-IV) and extends its half-life relative to native GHRH. The downstream rise in GH/IGF-1 drives lipolysis, with a notable effect on visceral (intra-abdominal) adipose tissue.

What the evidence shows

Human evidence is unusually strong for one specific population: HIV patients with lipodystrophy. Two pivotal phase 3 randomized, placebo-controlled trials and their pooled analysis (Falutz et al., JAIDS 2010 and J Clin Endocrinol Metab 2010) showed roughly a 15-18% reduction in visceral adipose tissue over 26 weeks, with regain after discontinuation, supporting the FDA approval. Stanley et al. (JAMA 2014; PMID 25038357) and a randomized NAFLD trial (Stanley et al., Lancet HIV 2019; PMID 31611038) further demonstrated reductions in liver fat and a lower rate of fibrosis progression in HIV-associated fatty liver disease. Crucially, nearly all rigorous human data come from HIV-positive cohorts; use for general anti-aging, body recomposition, or NAFLD in HIV-negative people is extrapolation and has not been established in large controlled trials. Subcutaneous fat and total weight are largely unaffected, and effects reverse when treatment stops.

Safety considerations

The most consistent documented concerns are glucose-related: because it raises GH/IGF-1, tesamorelin can worsen insulin sensitivity and glucose tolerance, and IGF-1 levels are monitored in clinical practice. Common adverse effects in trials included injection-site reactions, arthralgia, myalgia, peripheral edema, and paresthesia; hypersensitivity reactions have occurred. It is contraindicated in pregnancy and in people with active malignancy, since elevated IGF-1 is a theoretical tumor-growth concern, and in those with disrupted hypothalamic-pituitary axis (e.g., pituitary tumor/surgery, head irradiation). The NIH LiverTox database assigns it a low likelihood of causing clinically apparent liver injury. Long-term safety beyond the trial windows, and safety in non-HIV populations, remains poorly characterized.

Regulatory status

FDA-approved (2010, as Egrifta; reformulated as Egrifta SV in 2019 and the F8 formulation Egrifta WR in 2023) solely to reduce excess visceral abdominal fat in HIV-infected adults with lipodystrophy. All other uses are off-label, and it is a prescription drug, not a dietary supplement.

1. [1]Effects of tesamorelin, a growth hormone-releasing factor, in HIV-infected patients with abdominal fat accumulation: a randomized placebo-controlled trial (phase 3) — J Acquir Immune Defic Syndr, 2010, PMID 20101189 (Falutz J et al.)
2. [2]Effect of tesamorelin on visceral fat and liver fat in HIV-infected patients with abdominal fat accumulation: a randomized clinical trial — JAMA, 2014, PMID 25038357 (Stanley TL et al.)
3. [3]Effects of tesamorelin on non-alcoholic fatty liver disease in HIV: a randomised, double-blind, multicentre trial — Lancet HIV, 2019, PMID 31611038 (Stanley TL et al.)
4. [4]Tesamorelin - LiverTox: Clinical and Research Information on Drug-Induced Liver Injury — NIH/NIDDK LiverTox, NCBI Bookshelf (NBK548730)

• Approved for a narrow indication; broad anti-aging / general GH-boosting use is neither approved nor proven.
• Raises IGF-1; caution around active malignancy and other label contraindications — see the FDA label.

Stack fit

Why not S: held back by remaining gaps and limited replication.

Why not B: supported by human evidence, preclinical depth, mechanism confidence, safety clarity, regulatory clarity, practical relevance.

What would move it up: Larger controlled human trials, clearer long-term safety, replicated findings, and regulatory progress.

What would move it down: Failed confirmatory trials, new safety signals, or evidence that popular claims don't translate.

• Tesamorelin is an FDA-approved drug for specific indications.
• It belongs to the Growth-hormone secretagogues class.
• Its principal mechanism is characterized in the literature.

• Long-term safety in healthy users, and full drug-interaction risk.
• Claim-by-claim verdicts — these are authored against verified sources and shown when complete.

1. What it is
2. The GHRH signalling mechanism
3. The approval lane
4. Why Established, and not higher or lower
5. Proven lane vs speculative lane
6. What people report
7. Regulatory status
8. What changed recently