Peptide Evidence Index

Tesamorelin

Evidence last reviewed: September 2026

Quick answers

What is it?: Tesamorelin is a synthetic, stabilized analog of human growth-hormone-releasing hormone (GHRH) that stimulates the pituitary gland to release the body's own growth hormone.
Why are people interested in it?: It is an FDA-approved prescription medicine, but for one narrow use -- excess abdominal fat in HIV-infected adults with lipodystrophy -- not for general weight loss or anti-aging.
What has actually been studied?: Randomized, placebo-controlled Phase 3 trials in hundreds of HIV-infected adults with abdominal fat accumulation, plus smaller follow-up studies on inflammation, metabolism, and liver fat.
How strong is the evidence?: Solid randomized evidence for its one approved use in HIV-associated lipodystrophy; essentially no trial evidence exists for weight loss, muscle building, or anti-aging in people without HIV.
What don't we know yet?: Effects in people without HIV, and what happens with use beyond about a year, are not established by the existing trial evidence.
Where can I read the original research?: Sources at the bottom of this page: Falutz et al., New England Journal of Medicine 2007; Falutz et al., Journal of Clinical Endocrinology & Metabolism 2010.

Plain-English overview

Tesamorelin is a synthetic, stabilized analog of human growth-hormone-releasing hormone (GHRH), the hypothalamic hormone that tells the pituitary gland to release growth hormone. Rather than supplying growth hormone directly, it works upstream, stimulating the body's own pituitary to release more of it, which in turn raises insulin-like growth factor 1 (IGF-1). Its only FDA approval, granted in 2010 under the brand name Egrifta, is narrow: reduction of excess visceral abdominal fat in HIV-infected adults with lipodystrophy, a fat-redistribution syndrome linked to antiretroviral therapy. It is not approved for weight loss in the general population, age-related growth hormone decline, or athletic or bodybuilding use, and the World Anti-Doping Agency prohibits it at all times in competitive sport.

What researchers are studying it for

reduction of excess visceral abdominal fat in HIV-associated lipodystrophy

Current evidence level

Randomized trials

Regulatory status: Approved medicine. Evidence strength and approval are scored separately; approval is a regulatory decision about a specific use, not a measure of how much research exists.

Human research

The original 412-person registration trial randomized HIV-infected adults with excess abdominal fat to daily tesamorelin or placebo for 26 weeks; visceral fat measured by CT scan decreased 15.2% with tesamorelin and increased 5.0% with placebo, while triglycerides, the cholesterol-to-HDL ratio, and IGF-1 all improved significantly with tesamorelin (Falutz et al., 2007, New England Journal of Medicine). A pooled analysis of two Phase 3 trials with a 26-week safety extension, covering 806 participants, found the visceral-fat reduction sustained through 52 weeks in those who stayed on treatment, at roughly 17.5% relative to original baseline, alongside sustained lipid improvements and no clinically meaningful change in glucose measures (Falutz et al., 2010, Journal of Clinical Endocrinology & Metabolism). A follow-up analysis of 410 of these participants found tesamorelin significantly reduced a clotting-related inflammatory marker (tissue plasminogen activator antigen) relative to placebo, with changes correlated to the degree of visceral-fat loss (Stanley et al., 2011, AIDS). A post hoc analysis distinguishing "responders" (patients with at least 8% visceral-fat reduction) from non-responders found responders had significantly better triglyceride, glucose, and adiponectin outcomes over 52 weeks, while non-responders saw little metabolic benefit (Stanley et al., 2012, Clinical Infectious Diseases). A smaller, 50-person, 6-month trial found tesamorelin also reduced liver fat, not just visceral fat, though fasting glucose rose transiently at 2 weeks before normalizing by 6 months (Stanley et al., 2014, JAMA).

Animal and preclinical research

The material reviewed for this entry does not describe an animal-only preclinical literature for tesamorelin separate from its human trial program; its development proceeded through direct human trials in the approved indication.

Major findings

The pivotal 412-person trial found visceral fat decreased 15.2% with tesamorelin versus an increase of 5.0% with placebo over 26 weeks, with parallel improvements in triglycerides and cholesterol ratio (Falutz et al., 2007).
A pooled 806-person analysis found the fat-reduction effect sustained through 52 weeks of continued treatment, at roughly 17.5% relative to original baseline (Falutz et al., 2010).
Visceral-fat reduction reversed when participants switched from tesamorelin to placebo, while those who continued treatment maintained it, indicating the effect does not persist after stopping.
Tesamorelin significantly reduced a clotting-related inflammatory marker in proportion to visceral-fat loss (Stanley et al., 2011).
Patients with at least 8% visceral-fat reduction ("responders") showed significantly better triglyceride and glucose outcomes than non-responders over 52 weeks (Stanley et al., 2012).
A smaller 50-person trial found tesamorelin also reduced liver fat over 6 months, alongside a transient early rise in fasting glucose that normalized by 6 months (Stanley et al., 2014).

What has not been established

Effects in people without HIV are not established; every pivotal trial enrolled HIV-infected adults with antiretroviral-associated fat redistribution.
Long-term use beyond about a year is not covered by the pivotal trial data.
Athletic, bodybuilding, or general anti-aging use has essentially no trial evidence; tesamorelin is prohibited at all times in competitive sport under WADA rules.
Whether the transient early glucose rise seen in one small trial has any longer-term significance.

Important limitations

All pivotal efficacy trials enrolled HIV-infected adults on stable antiretroviral therapy with specific waist-circumference criteria -- a distinct population and physiology from ordinary age- or diet-related visceral fat.
Trials excluded people with a BMI under 20, active malignancy, pituitary disease, or untreated hypothyroidism.
The main registration trial's results exist because the sponsor published them in a peer-reviewed journal; the ClinicalTrials.gov record itself shows no results posted directly.
The largest trials ran 26-52 weeks; data on multi-year use is limited.

Regulatory status

Tesamorelin was approved by the FDA as Egrifta in November 2010 for a single, narrow indication: reduction of excess abdominal fat in HIV-infected patients with lipodystrophy. It is not approved for weight loss in the general population, age-related growth hormone decline, or athletic or bodybuilding use, and the World Anti-Doping Agency prohibits it at all times in competitive sport under its category covering GHRH and its analogues.

Primary research sources

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. PMID: 18057338
Falutz J, et al. Effects of tesamorelin (TH9507), a growth hormone-releasing factor analog, in HIV-infected patients with excess abdominal fat: a pooled analysis of two Phase 3 trials: J Clin Endocrinol Metab 2010;95(9):4291-304. PMID: 20554713
Stanley TL, et al. Effects of tesamorelin on inflammatory markers in HIV patients with excess abdominal fat: AIDS 2011;25(10):1281-8. PMID: 21516030
Stanley TL, et al. Reduction in visceral adiposity is associated with an improved metabolic profile in HIV-infected patients receiving tesamorelin: Clin Infect Dis 2012;54(11):1642-51. PMID: 22495074
Stanley TL, et al. Effect of tesamorelin on visceral fat and liver fat in HIV-infected patients with abdominal fat accumulation: JAMA 2014;312(4):380-9. PMID: 25038357
TH9507 in Patients With HIV-Associated Lipodystrophy: ClinicalTrials.gov NCT00123253, n=412, completed 2007

Full evidence entry (complete data, registry records, dosing evidence)

Approved medicine

Approved by a major regulator for a specific use

At a glance

Also known as: Egrifta, TH9507
Class: Growth hormone-releasing hormone (GHRH) analog
Derived from: A synthetic, stabilized analog of human growth hormone-releasing hormone (GHRH 1-44) that stimulates the pituitary gland to release the body's own growth hormone, rather than supplying growth hormone directly
Registered human trials: 24
…with published results: at least the pivotal trial and pooled analysis below; most of the 24 registered studies are completed, but posted results were not individually verified for each (counted on ClinicalTrials.gov this session)
Largest human trial: 806 HIV-infected adults with excess abdominal fat, pooled across two Phase 3 trials (Falutz et al., 2010) — tesamorelin reduced visceral adipose tissue by roughly 15-18% relative to baseline over 26-52 weeks, versus an increase with placebo
Studied for: reduction of excess visceral abdominal fat in HIV-associated lipodystrophy
Dosing evidence: Prescribed by a clinicianThe approved dose is a fixed once-daily injection studied specifically in HIV-infected adults with a defined pattern of visceral fat accumulation — not a dose established for, or studied in, general fat loss or non-HIV populations.
Regulatory status: Approved by the FDA as Egrifta in November 2010 for a single, narrow indication: reduction of excess abdominal fat in HIV-infected patients with lipodystrophy. It is not approved for weight loss in the general population, for age-related growth hormone decline, for athletic or bodybuilding use, or for any indication outside HIV-associated fat redistribution.
Anti-doping status: Prohibited at all times by the World Anti-Doping Agency under class S2 (peptide hormones, growth factors, and related substances), which explicitly names growth hormone-releasing hormones and their analogues, including tesamorelin

What it is

Tesamorelin is a synthetic, stabilized analog of human growth hormone-releasing hormone (GHRH) — the hypothalamic hormone that tells the pituitary gland to release growth hormone. Unlike direct growth hormone injections, tesamorelin works upstream: it stimulates the body's own pituitary to release more of its own growth hormone, which in turn raises insulin-like growth factor 1 (IGF-1).

Its only FDA approval is narrow: reduction of excess visceral abdominal fat in HIV-infected patients with lipodystrophy, a fat-redistribution syndrome linked to antiretroviral therapy that causes visceral fat accumulation alongside loss of fat in the face and limbs. It is not approved for weight loss generally, for age-related growth hormone decline, for athletic or bodybuilding use, or for any population outside this specific HIV-associated condition.

What the studies actually found

The original registration trial (Falutz et al., NEJM 2007; PubMed PMID 18057338, DOI) randomized 412 HIV-infected adults with excess abdominal fat accumulation (86% men) to a daily subcutaneous injection of tesamorelin or placebo for 26 weeks. Visceral adipose tissue, measured by CT scan, decreased 15.2% with tesamorelin and increased 5.0% with placebo. Triglycerides and the ratio of total cholesterol to HDL cholesterol also improved significantly with tesamorelin, and IGF-1 levels rose 81.0% versus a 5.0% decline with placebo — confirming the drug was doing what it was designed to do, separately from its effect on fat.

A pooled analysis of two Phase 3 trials with a 26-week safety extension (Falutz et al., J Clin Endocrinol Metab 2010; PubMed PMID 20554713, DOI) combined 806 participants (543 initially on tesamorelin, 263 on placebo) and found the visceral-fat reduction was sustained through 52 weeks in those who stayed on the drug — roughly 17.5-18% relative to original baseline — alongside sustained lipid improvements and no clinically meaningful change in glucose measures.

What exists in humans

24 studies listing tesamorelin as an intervention are registered on ClinicalTrials.gov as of this session — a much smaller registry than the GLP-1 drugs above, consistent with a single narrow approved indication and a smaller market. The original 412-person registration trial (NCT00123253) itself shows no results posted directly on the registry; its findings exist because the sponsor published them in a peer-reviewed journal, not because ClinicalTrials.gov displays them. That is a useful reminder that a registry record showing no posted results does not always mean a trial went unpublished — but it does mean the registry itself is not where to find the answer.

The registration trials enrolled HIV-infected adults on stable antiretroviral therapy, using specific waist-circumference and waist-to-hip-ratio thresholds to define "excess abdominal fat." That is not the same population, or the same physiological kind of fat accumulation, as ordinary age- or diet-related visceral fat in someone without HIV. Trials excluded people with a BMI under 20, active malignancy, pituitary disease or a history of pituitary surgery, and untreated hypothyroidism.

What doses have been studied in humans

The pivotal trial gave 412 HIV-infected adults with excess abdominal fat a fixed once-daily subcutaneous injection for 26 weeks, with visceral adipose tissue on CT scan as the primary endpoint. The pooled Phase 3 analysis followed 806 participants across two identically dosed trials through a 26-week extension, for 52 weeks total, tracking the same fat, lipid, and IGF-1 measures.

This is a prescription medicine approved for one specific condition, and the approved dose and administration schedule are set by the FDA label for that HIV-associated indication, determined by a prescriber managing a patient's HIV care — not extrapolated from a trial protocol for use in a different population or for a different purpose. Nothing here describes what a reader should take, and nothing here supports using tesamorelin outside HIV-associated lipodystrophy.

What remains unknown

Effects in people without HIV are not established by this evidence base at all. Every pivotal trial enrolled HIV-infected adults with antiretroviral-associated fat redistribution, a physiologically distinct situation from ordinary visceral fat.
What happens after stopping was addressed directly in the trial program: in the extension study, participants who switched from tesamorelin to placebo had their visceral-fat reduction reverse, while those who continued tesamorelin maintained it — indicating the effect does not persist without continued treatment.
Long-term use beyond about a year is not covered by the pivotal trial data, which ran 26 weeks in the main phase and 52 weeks with the extension.
Athletic, bodybuilding, or anti-aging use has essentially no trial evidence — the entire pivotal evidence base is specific to HIV-associated lipodystrophy, and the drug is prohibited in competitive sport at all times under WADA's category covering GHRH and its analogues.

Registry and study records

TH9507 in Patients With HIV-Associated Lipodystrophy: ClinicalTrials.gov NCT00123253 · n=412, completed 2007, no results posted on the registry itself; findings published separately by Falutz et al., NEJM 2007

See the full Evidence Index →

Evidence last reviewed: September 2026. Peptide Proof reports what studies found. We do not give medical advice, dosing guidance, or treatment recommendations.