Tesamorelin

What it is

Tesamorelin is a synthetic analogue of growth hormone-releasing hormone, also called growth hormone-releasing factor (GHRF)^{[1 ]}. It is marketed in the United States as Egrifta SV and Egrifta WR for a narrow FDA-approved indication: reduction of excess abdominal fat in HIV-infected adult patients with lipodystrophy^{[1 –2 ]}. The drug is not indicated for weight-loss management, and its FDA labeling states that it has a weight-neutral effect in the approved clinical-trial population^{[1 –2 ]}.

Chemical structure

Tesamorelin is a 44-amino-acid analogue of human GHRF with a hexenoyl moiety attached to the N-terminal tyrosine residue^{[1 ]}. The FDA-approved Egrifta WR label lists the molecular weight of tesamorelin free base as 5,135.9 Da and describes tesamorelin as prepared as an acetate salt^{[1 ]}. This modification differentiates tesamorelin from endogenous GHRH while preserving receptor activity at the human GHRF receptor^{[1 ]}.

Mechanism

Tesamorelin binds and stimulates human GHRF receptors with similar potency to endogenous GHRF in vitro^{[1 ]}. GHRF is a hypothalamic peptide that stimulates pituitary somatotroph cells to synthesize and release endogenous growth hormone in pulses^{[1 ]}. Growth hormone then acts on multiple tissues directly and through downstream mediators such as insulin-like growth factor 1 (IGF-1)^{[1 ]}. In clinical trials, tesamorelin increased growth hormone secretion and increased IGF-1 and IGFBP-3 without clinically significant changes in other measured pituitary hormones such as TSH, LH, ACTH, or prolactin^{[1 ]}.

Approved products and formulations

Tesamorelin was first approved in the United States in 2010 for HIV-associated lipodystrophy^{[1 ,3 ]}. Earlier Egrifta formulations required daily reconstitution; Egrifta SV was introduced as a smaller-volume daily injection, and Egrifta WR was approved in March 2025 as a newer formulation that still uses daily subcutaneous injection but requires weekly rather than daily reconstitution^{[1 ,4 ]}. Egrifta WR and Egrifta SV are not substitutable because the formulations, strengths, reconstitution instructions, storage requirements, and recommended dosages differ^{[1 ]}.

Administration

Approved tesamorelin products are administered by subcutaneous injection into the abdomen with rotation of injection sites^{[1 –2 ]}. This page describes FDA-approved product forms, regulatory status, and published research; it does not provide dosing instructions or individualized medical guidance.

Regulatory status

Tesamorelin is FDA-approved in the United States as a prescription drug for reduction of excess abdominal fat in HIV-infected adult patients with lipodystrophy^{[1 –2 ]}. FDA labeling includes three important limitations: long-term cardiovascular safety has not been established; the product is not indicated for weight-loss management; and there are no data showing improved adherence to antiretroviral therapy in HIV-positive patients taking tesamorelin^{[1 –2 ]}.

Approval timeline

Egrifta’s initial U.S. approval was in 2010^{[1 ]}. Egrifta SV is a 2 mg per vial formulation; Egrifta WR is an 11.6 mg per vial formulation approved in March 2025^{[1 –2 ,4 ]}. Theratechnologies announced in September 2025 that specialty pharmacies were ordering Egrifta WR and that the WR formulation would gradually replace Egrifta SV during a transition period^{[5 ]}. A separate April 2025 company announcement stated that FDA had approved a Prior Approval Supplement for Egrifta SV, allowing regular distribution after a period of supply uncertainty^{[6 ]}.

Compounding policy

Compounding status should be interpreted conservatively. FDA’s general 503A framework states that state-licensed pharmacies and physicians compounding from bulk substances must use substances that comply with an applicable USP or NF monograph, are components of FDA-approved drugs if no monograph exists, or appear on FDA’s 503A bulks list if neither of those pathways applies^{[7 ]}. FDA’s 503B framework states that outsourcing facilities may use a bulk drug substance only if the substance appears on the 503B bulks list or the compounded drug appears on FDA’s drug shortage list at the time of compounding, distribution, and dispensing^{[8 ]}. Tesamorelin was not identified on FDA’s April 22, 2026 503A category list or the final 503B bulks list reviewed for this draft^{[9 –10 ]}.

Because FDA-approved tesamorelin products are commercially available, routine compounding of copies would also raise “essentially a copy” issues under federal compounding law^{[7 –8 ]}. Any claimed compounded tesamorelin pathway should be reviewed against the live FDA shortage database, applicable 503A/503B requirements, biologics and drug compounding law, and the specific product facts. ProPeptideGuide should not list compounded tesamorelin vendors without legal review.

Controlled-substance and anti-doping status

Tesamorelin is not listed in the federal controlled-substance schedules in 21 CFR Part 1308^{[11 ]}. For athletes, regulatory status is different from anti-doping status: USADA states that growth hormone-releasing factors are prohibited under the WADA Prohibited List, so athletes subject to testing should treat tesamorelin as a prohibited performance-related substance unless a valid therapeutic-use pathway applies^{[12 ]}. Last regulatory verification: May 5, 2026.

Research summary

The central evidence base for tesamorelin is HIV-associated abdominal fat accumulation.

Pivotal HIV lipodystrophy trials

FDA labeling summarizes two multicenter, randomized, double-blind, placebo-controlled studies in HIV-infected adults with lipodystrophy and excess abdominal fat^{[1 ]}. Study 1 randomized 412 patients and Study 2 randomized 404 patients to tesamorelin or placebo for 26 weeks, followed by extension phases in which responders were rerandomized to continue tesamorelin or switch to placebo^{[1 ]}. The primary endpoint was percent change in visceral adipose tissue (VAT) measured by CT scan at the L4–L5 vertebral level^{[1 ]}.

In the main 26-week phases, tesamorelin reduced VAT more than placebo in both pivotal studies^{[1 ]}. FDA labeling reports mean VAT reductions of 18% versus a 2% increase in Study 1, and 14% versus a 2% decrease in Study 2^{[1 ]}. Weight did not meaningfully change, consistent with the label’s statement that Egrifta WR is not a weight-loss medication^{[1 ]}. Waist circumference decreased modestly, IGF-1 and IGFBP-3 increased, and mean lean body mass increased in both studies compared with placebo^{[1 ]}.

Falutz long-term and extension data

Falutz and colleagues published the 404-person randomized trial with extension data in Journal of Acquired Immune Deficiency Syndromes in 2010^{[13 ]}. In that trial, VAT decreased by 10.9% in the tesamorelin group versus 0.6% in the placebo group during the 6-month primary phase, and participants who continued tesamorelin for 12 months had an approximately 18% VAT reduction^{[13 ]}. Participants who switched from tesamorelin to placebo rapidly lost the initial VAT improvement, indicating that the effect was not durable after discontinuation in that study^{[13 ]}.

A long-term safety and extension analysis published in AIDS in 2008 also found that continuing tesamorelin helped maintain visceral-fat reduction, while switching to placebo led to reaccumulation^{[14 ]}. The label’s 52-week extension data similarly show that patients who continued tesamorelin maintained VAT reduction better than those switched to placebo^{[1 ]}. These findings support the approved indication but also underscore that tesamorelin is a chronic pharmacologic intervention for a defined HIV-associated condition, not a one-time cosmetic abdominal-fat treatment.

Metabolic and glycemic outcomes

Metabolic outcomes were mixed and clinically important. A pooled analysis in Clinical Infectious Diseases found that among tesamorelin-treated participants, those with at least 8% VAT reduction had improved triglyceride patterns and relatively unchanged glucose homeostasis compared with nonresponders^{[15 ]}. The FDA label reports that patients receiving Egrifta in clinical trials had an increased risk of developing diabetes by HbA1c criteria compared with placebo, with 5% versus 1% reaching HbA1c of at least 6.5% during the first 26 weeks^{[1 ]}. This is why glucose evaluation and monitoring appear prominently in labeling^{[1 ]}.

HIV-associated NAFLD/MASLD — investigational

Tesamorelin has also been studied for liver fat in people with HIV, but it is not FDA-approved for NAFLD, MASLD, MASH, or NASH as of this review date^{[1 ]}. In a 2014 JAMA randomized trial of 50 antiretroviral-treated adults with HIV and abdominal fat accumulation, tesamorelin reduced VAT and liver fat over 6 months compared with placebo^{[16 ]}. The authors described the liver-fat finding as preliminary and called for further studies to determine clinical importance and long-term consequences^{[16 ]}.

A later randomized, double-blind, multicenter trial in The Lancet HIV studied 61 people with HIV-associated NAFLD over 12 months^{[17 ]}. NIH’s summary of the trial reported that 35% of tesamorelin-treated participants achieved a normal hepatic fat fraction compared with 4% on placebo, and that fibrosis onset or worsening occurred in two tesamorelin-treated participants versus nine placebo-treated participants^{[18 ]}. These results are scientifically notable, but they do not change the current FDA-approved indication^{[1 ,17 –18 ]}. Subsequent transcriptomic and proteomic analyses explored possible mechanisms, including changes in inflammatory and fibrotic pathways, but these were secondary mechanistic analyses rather than approval-enabling outcomes^{[19 –20 ]}.

Cognition and aging — exploratory

A smaller body of research has investigated tesamorelin or GHRH-analog stimulation in aging and cognition. Baker and colleagues randomized 152 adults aged 55 to 87 years, including adults with mild cognitive impairment and healthy older adults, to daily tesamorelin or placebo for 20 weeks^{[21 ]}. The trial reported favorable effects on cognitive composite measures and increased IGF-1, but this was not an FDA-approved indication and has not become a standard dementia or anti-aging therapy^{[21 ]}. This evidence should not be generalized into claims that tesamorelin treats Alzheimer disease, reverses aging, or improves performance in healthy adults.

Where the evidence ends

Overall, the evidence is strongest for the FDA-approved HIV lipodystrophy indication, with two substantial randomized trials, extension data, and regulatory review^{[1 ,13 –14 ]}. Evidence for HIV-associated liver disease is promising but investigational^{[16 –20 ]}. Evidence for cognition and aging is exploratory^{[21 ]}. Claims about bodybuilding, general fat loss, longevity, or wellness use are not supported by the same level of evidence and should not be presented as established clinical uses.

Public discourse

Curtis Rosebraugh, MD, MPH, an FDA Office of Drug Evaluation II official, framed the original Egrifta approval around a recognized need for therapies for HIV-associated lipodystrophy and quality-of-life concerns^{[22 ]}.

Anthony S. Fauci, MD, then Director of NIAID, discussed tesamorelin’s investigational liver-disease findings in the context of people with HIV living longer while still facing liver comorbidity^{[18 ]}.

Christian Marsolais, PhD, Chief Medical Officer at Theratechnologies, described Egrifta WR from the manufacturer’s perspective as a more convenient formulation for a narrowly defined HIV lipodystrophy indication^{[5 ]}.

Paul E. Sax, MD, an HIV clinician and NEJM Journal Watch contributor, described the approval as clinically welcome while emphasizing unresolved questions about durability, safety, and clinical endpoints beyond visceral-fat reduction^{[23 ]}.

Public discourse reflects the views of the speakers cited and does not represent medical advice or the editorial position of ProPeptideGuide.

Side effects and safety

Tesamorelin labeling includes several contraindications. Egrifta WR is contraindicated in patients with disruption of the hypothalamic–pituitary axis due to hypophysectomy, hypopituitarism, pituitary tumor or surgery, head irradiation, or head trauma; patients with active malignancy; patients with known hypersensitivity to tesamorelin or excipients; and pregnant women^{[1 ]}. The pregnancy contraindication is based on lack of benefit from modifying pregnancy-associated visceral adipose changes and potential fetal harm^{[1 ]}.

The label warns about increased risk of neoplasms because tesamorelin induces endogenous growth hormone release and increases IGF-1, a growth factor^{[1 ]}. Patients with active malignancy should not be treated, and patients with a history of malignancy require careful benefit–risk evaluation^{[1 ]}. Labeling also states that the effects of prolonged IGF-1 elevations are unknown and recommends monitoring IGF-1 during therapy^{[1 ]}.

Common adverse reactions

Common adverse reactions include musculoskeletal and injection-site effects. The Egrifta WR label lists arthralgia, injection-site erythema, injection-site pruritus, pain in extremity, peripheral edema, and myalgia among the most common adverse reactions^{[1 ]}. In clinical trials, injection-site reactions occurred in 25% of Egrifta-treated patients and 14% of placebo-treated patients during the first 26 weeks^{[1 ]}. Hypersensitivity reactions occurred in 4% of Egrifta-treated patients and included pruritus, erythema, flushing, urticaria, and rash^{[1 ]}.

Glucose effects

Glucose effects require particular attention. FDA labeling states that Egrifta WR can result in glucose intolerance, and clinical trials showed a higher proportion of treated participants reaching HbA1c of at least 6.5% compared with placebo^{[1 ]}. The label recommends evaluating glucose status before treatment and monitoring periodically during treatment^{[1 ]}. It also notes that because tesamorelin increases IGF-1, patients with diabetes should be monitored for potential development or worsening of retinopathy^{[1 ]}.

Drug interactions

Drug-interaction concerns relate to downstream growth hormone physiology rather than classic CYP inhibition by tesamorelin itself. The label states that growth hormone may alter clearance of drugs metabolized by CYP450 enzymes and advises monitoring when Egrifta WR is used with CYP450-metabolized drugs^{[1 ]}. It also warns that patients receiving glucocorticoid replacement for hypoadrenalism may require adjusted maintenance or stress doses after starting therapy because growth hormone can inhibit 11β-hydroxysteroid dehydrogenase type 1^{[1 ]}.

Long-term safety

Long-term cardiovascular safety has not been established^{[1 ]}. The pivotal trials measured VAT reduction and related endpoints, not hard outcomes such as myocardial infarction, stroke, mortality, or long-term liver outcomes^{[1 ,13 –14 ]}. Safety findings from FDA-approved products should not be extrapolated to non-prescription, research-chemical, or purported compounded tesamorelin products, where identity, sterility, potency, storage, and labeling cannot be assumed.

Available through

FDA-approved tesamorelin is available in the United States by prescription through compliant channels for patients who meet the approved indication and other prescribing requirements^{[1 –2 ,5 ]}. Egrifta WR and Egrifta SV are specialty prescription products, and current access may depend on clinician evaluation, pharmacy availability, insurance coverage, and product transition status from Egrifta SV to Egrifta WR^{[5 –6 ]}.

Telehealth platform partnerships are pending verification. Provider listings will be added only after legal and editorial review confirms that the platform prescribes FDA-approved tesamorelin through licensed clinicians and dispenses through compliant specialty pharmacy channels. ProPeptideGuide does not link to or endorse gray-market vendors, research-chemical sites, or compounded tesamorelin products marketed for bodybuilding, anti-aging, weight loss, or non-approved wellness use.