Tesamorelin

Overview

Tesamorelin is a synthetic 44-amino-acid analog of human growth-hormone-releasing hormone (GHRH), chemically modified with a trans-3-hexenoyl group on its N-terminal tyrosine to resist enzymatic degradation. Unlike most peptides discussed elsewhere on this site, tesamorelin is a genuinely FDA-approved prescription drug, not a compounded or research-chemical peptide. It's approved under the brand names Egrifta and Egrifta SV (current formulation, made by Theratechnologies) for reduction of excess visceral abdominal fat in HIV-infected patients with lipodystrophy.¹

Also known as: tesamorelin, trans-3-hexenoyl-hGHRH(1-44)-NH2, or by its development code TH9507. It has a well-documented Phase 3 registration trial program — the "LIPO" trials — published in the New England Journal of Medicine and JAMA.¹³ Off-label use — for general visceral fat reduction, non-HIV fatty liver disease, or GH-axis support in patients without HIV — is common in cosmetic and longevity medicine. That off-label use is not backed by the same registration-trial rigor as the approved indication, and this page is clear about that distinction throughout.

Because Egrifta SV is a commercially manufactured, FDA-approved finished drug product, it's often dispensed directly through specialty pharmacy rather than 503A-compounded from bulk substance — though bulk tesamorelin compounding does occur in some clinics for cost or dosing-flexibility reasons, and is subject to standard 503A rules since tesamorelin is not on the FDA's restricted Category 2 list.

How it works

Tesamorelin activates the GHRH receptor, a Gαs-coupled receptor on anterior pituitary somatotrophs, stimulating pulsatile, physiologic endogenous GH secretion — the same receptor and downstream cAMP/PKA pathway used by sermorelin and CJC-1295. Its key chemical innovation is the N-terminal trans-3-hexenoyl modification, shown to render the peptide resistant to dipeptidyl aminopeptidase-IV (DPP-IV) — the enzyme that rapidly degrades native GHRH and limits sermorelin's half-life to roughly 11–12 minutes. This modification slowed degradation in rat, dog, and human plasma without disrupting receptor binding.

Despite this DPP-IV resistance, tesamorelin's apparent elimination half-life remains short by small-molecule standards — approximately 21–45 minutes in animal models — but that's sufficient for effective once-daily dosing, because the pharmacodynamic effect on the GH/IGF-1 axis outlasts the drug's direct plasma exposure. Daily subcutaneous dosing produces sustained GH and IGF-1 elevation; in the pivotal Phase 3 trials, IGF-1 rose approximately 81–108% above baseline versus a slight decline in the placebo group.¹ Administration is subcutaneous, injected into the abdomen, once daily, per FDA labeling.

What the research shows

Animal / preclinical evidence

Preclinical work by Ferdinandi and colleagues established that the trans-3-hexenoyl modification confers DPP-IV resistance in rat, dog, and human plasma models, the biochemical basis for tesamorelin's clinical activity and the rationale that carried it into human trials.

Human evidence

The pivotal trial: Falutz et al. (2007) randomized 412 HIV-infected patients (86% male) with abdominal fat accumulation to 2 mg subcutaneous tesamorelin daily or placebo for 26 weeks. Visceral adipose tissue fell 15.2% with tesamorelin versus a 5.0% increase with placebo (p<0.001); triglycerides dropped roughly 50 mg/dL versus a 9 mg/dL rise with placebo (p<0.001); IGF-1 rose 81.0% versus a 5.0% decline with placebo (p<0.001), with no significant difference in glycemic measures between groups.¹ A pooled analysis of two confirmatory Phase 3 trials (n≈806) confirmed a treatment effect of about -15.4% visceral fat and -12.3% triglycerides at 26 weeks, largely maintained through 52 weeks in a safety extension — the second pivotal dataset required for FDA approval.²

Beyond the approved indication, a single-center RCT at Massachusetts General Hospital (n=50, 6 months) found tesamorelin reduced visceral fat by a net -42 cm² (95% CI -71 to -14, p=0.005) and also reduced liver fat (net -2.9% lipid-to-water ratio, p=0.003) — the first prospective evidence the mechanism extends to hepatic fat.³ A 12-month multicenter RCT in HIV-associated NAFLD (n=61) found tesamorelin reduced hepatic fat fraction by an absolute -4.1% (p=0.02), with 35% of tesamorelin patients reaching a normal fat fraction versus 4% on placebo (p=0.007), and slowed fibrosis progression — though it did not improve pre-existing fibrosis, and two participants discontinued due to hyperglycemia.⁴ A 2023 presentation confirmed the effect persists in HIV patients on modern integrase-inhibitor regimens,⁵ and a 2026 meta-analysis of five randomized trials reported a pooled hepatic-fat-fraction reduction of -4.28% (p<0.001) with no serious pooled adverse events.⁸

Honest limits: All of this trial evidence sits in HIV-infected populations. Tesamorelin is not FDA-approved, and has meaningfully less robust trial support, for general-population NAFLD, non-HIV visceral fat reduction, or anti-aging/GH-axis-support use in healthy adults. Off-label prescribing for those uses extrapolates from the HIV data and general GH-axis physiology — a real evidence base, but not the same one that earned FDA approval.

Typical use and dosing

The ranges below come from FDA labeling and published trials — presented for education, not as a prescribing recommendation. An Aurafil physician determines actual dosing individually.

Safety, side effects, and who should avoid it

Common side effects reported in trials and on the FDA label include injection-site reactions (erythema, itching, pain) — more frequent with tesamorelin than placebo across trials — arthralgia, peripheral edema, and myalgia. Because tesamorelin raises GH/IGF-1, it carries a labeled risk of reduced insulin sensitivity and hyperglycemia. In the 2019 NAFLD trial, two participants discontinued due to hyperglycemia, though the pivotal Phase 3 trials found no significant group-level glycemic difference over 26 weeks, aside from a transient early fasting-glucose rise.¹⁴

FDA labeling recommends monitoring IGF-1 levels and glycemic parameters (fasting glucose, HbA1c). Caution is warranted with other drugs affecting the GH/IGF-1 axis or glucose metabolism. It's also worth noting clinically that visceral and liver fat reductions generally aren't durable off-drug — fat tends to re-accumulate after discontinuation, meaning sustained benefit requires continued therapy.

Regulatory status

Tesamorelin (Egrifta SV) is FDA-approved — a genuine NDA-approved prescription drug, not a compounded or research-chemical product, for HIV-associated lipodystrophy.¹ It is not on the FDA's 503A Category 2 restricted-compounding list; compounded bulk tesamorelin, used by some clinics for cost or dosing-flexibility reasons in off-label settings, remains subject to ordinary 503A rules rather than a specific safety-risk prohibition.

Tesamorelin's approved indication is addressed in HIV clinical management guidelines as an option for visceral fat reduction in appropriately selected patients, though it isn't universally listed as first-line given cost and the need for continued therapy to maintain effect. The AACE/ACE 2019 Clinical Practice Guideline for Growth Hormone Deficiency in Adults discusses GHRH-axis therapies broadly but does not specifically endorse tesamorelin for non-HIV indications.⁶ No specialty society has issued a guideline endorsing tesamorelin for off-label NAFLD/NASH or general anti-aging use in non-HIV populations — that remains investigational, notwithstanding a promising and growing RCT dataset specifically in HIV-associated NAFLD.

Tesamorelin is explicitly named on the WADA 2026 Prohibited List, Section S2.2.4 ("growth hormone-releasing hormone and its analogues, e.g., CJC-1293, CJC-1295, sermorelin and tesamorelin") — prohibited at all times, in and out of competition.⁷ No FDA safety communication specific to tesamorelin has been issued during the 2023–2026 peptide-regulation wave, which focused on unapproved research peptides; tesamorelin's regulatory footing is unaffected since it's an approved drug, not a nominated bulk substance.

Frequently asked questions