Educational reference, not medical advice. This page summarizes information from published research and regulatory filings for educational purposes. It is not a recommendation to use any compound and should not replace guidance from a licensed healthcare provider. Most peptides discussed here are not approved for the uses described.
What it is
Tesamorelin is a synthetic analog of human growth hormone-releasing hormone (GHRH). It is identical to native GHRH(1-44) with a trans-3-hexenoic acid group attached to the N-terminal tyrosine. That modification protects the peptide from cleavage by dipeptidyl peptidase-4 (DPP-4), extending its functional half-life enough to make once-daily subcutaneous dosing practical.
It is the only GHRH analog with a currently active FDA approval in the United States, marketed by Theratechnologies under three brand names: Egrifta (original 2010 formulation), Egrifta SV (2019 reformulation with reduced injection volume), and Egrifta WR (2023, with weekly rather than daily reconstitution).
History
Theratechnologies developed tesamorelin (initially designated TH9507) in the early 2000s. The pivotal Phase III program enrolled HIV-positive adults with excess abdominal fat — a common complication of antiretroviral therapy at the time. The 2007 Falutz et al. paper in the New England Journal of Medicine reported a 15.2% reduction in visceral adipose tissue versus a 5.0% increase with placebo over 26 weeks. The 2010 long-term extension confirmed durability of the effect.
Approval timeline:
- November 2010 — FDA approves Egrifta for reduction of excess abdominal fat in HIV-infected patients with lipodystrophy.
- 2019 — FDA approves Egrifta SV, a reformulation that reduced the daily injection volume.
- 2023 — FDA approves Egrifta WR (weekly reconstitution), a formulation that allows patients to reconstitute the vial weekly rather than daily while still injecting daily.
The drug is also approved in Canada and several European countries for the same indication.
Regulatory status
Tesamorelin is FDA approved for the reduction of excess abdominal fat in HIV-infected patients with lipodystrophy — a specific indication tied to the metabolic syndrome that develops in some patients on long-term antiretroviral therapy. The label does not extend to general weight management, growth hormone deficiency, or anti-aging use.
The drug is approved by Health Canada and by some European national regulators on a country-by-country basis; the European Medicines Agency declined a centralized authorization in 2010.
The World Anti-Doping Agency lists tesamorelin under class S2 of the Prohibited List — banned in and out of competition.
Mechanism
Published mechanism papers describe tesamorelin as a GHRH receptor agonist on pituitary somatotrophs. Receptor activation stimulates pulsatile growth hormone release through the same cAMP pathway as native GHRH, and the resulting rise in GH and IGF-1 drives lipolysis preferentially in visceral fat.
In the Falutz program, IGF-1 rose into the upper third of the normal range and visceral fat decreased; insulin sensitivity and fasting glucose were monitored closely because GH excess can worsen glycemic control. Net effects on insulin resistance in trials were small and clinically modest.
Half-life and dosing intervals
The plasma half-life of tesamorelin is short — published estimates put it at 8 to 13 minutes in HIV-infected adults. Despite the brief exposure, daily subcutaneous injection produces sustained elevation of IGF-1 because each daily GH pulse drives multi-day IGF-1 turnover.
The FDA label for Egrifta SV specifies 2 mg subcutaneously once daily in the abdomen, rotating sites to reduce lipohypertrophy. The Phase III trials used the same 2 mg daily dose; lower doses were less effective and higher doses were not pursued.
Reconstitution example
Compounded tesamorelin is supplied lyophilized in 1 mg, 2 mg, or 11.6 mg vials. The branded Egrifta SV vial contains 2 mg of tesamorelin to be reconstituted with the supplied 2.1 mL sterile water diluent — the patient then withdraws 0.21 mL for a 2 mg dose.
For a compounded 2 mg vial reconstituted with 1 mL of bacteriostatic water, the concentration is 2 mg/mL — on a 1 mL U-100 insulin syringe, 100 units (1.0 mL) contains 2 mg. A larger 11.6 mg vial reconstituted with 5.8 mL yields 2 mg/mL, the same concentration, allowing the vial to cover roughly six daily doses. Vial's calculator handles the unit-to-mg conversion automatically.
What to know
- Specific indication. Tesamorelin is FDA-approved only for HIV-associated lipodystrophy. Off-label use exists but the published evidence base is largely confined to that population.
- Boxed warnings. The Egrifta label flags potential disease progression risks in patients with active malignancy and notes the need for monitoring glucose tolerance.
- Common side effects in the Falutz trials: injection-site reactions, arthralgia, peripheral edema, myalgia, and paresthesias. A subset of patients developed glucose intolerance or worsened pre-existing diabetes.
- Contraindications. Disrupted hypothalamic-pituitary axis (after radiation, surgery, or trauma), active malignancy, pregnancy.
- WADA banned. Use is prohibited in competitive sport.
- Storage. Refrigerate lyophilized vials. After reconstitution with the supplied diluent, Egrifta and Egrifta SV are stable for hours and should be used promptly; Egrifta WR was specifically designed for a longer post-reconstitution stability window — refer to the label for the exact period.
Sources
- 1.Falutz J et al. (2007). Metabolic effects of a growth hormone-releasing factor in patients with HIV. New England Journal of Medicine.
- 2.Falutz J et al. (2010). Long-term safety and effects of tesamorelin, a growth hormone-releasing factor analogue, in HIV patients with abdominal fat accumulation. AIDS.
- 3.Stanley TL et al. (2014). Effects of tesamorelin on inflammatory markers in HIV patients with excess abdominal fat: relationship with visceral adipose reduction. AIDS.
- 4.FDA Prescribing Information — Egrifta (tesamorelin) for injection.
- 5.World Anti-Doping Agency — Prohibited List (S2).