Tesamorelin (Egrifta): an approved GHRH analogue, and what its label actually covers

Tesamorelin is what a GHRH analogue looks like after it has been through the full drug-approval process: two phase 3 trials, a label with five warnings, an immunogenicity section, and three formulations with different storage rules. It is also the peptide most often used to lend borrowed credibility to the ones that have not been through any of that.

What it is

Tesamorelin is a synthetic analogue of the full 44-amino-acid human GHRH with a trans-3-hexenoic acid group on the N-terminus that protects it from rapid breakdown. It stimulates the pituitary to release growth hormone in a pulsatile pattern, raising IGF-1. Theratechnologies developed it under the code TH9507 for the visceral fat accumulation seen in people with HIV on long-term antiretroviral therapy.

The human evidence

All of it is in people with HIV. There is no randomised trial of tesamorelin for abdominal fat, muscle, sleep or cognition in people without HIV that would support the way it is marketed by "longevity" clinics. The label says so directly: Egrifta "is not indicated for weight loss management."

Regulatory status

FDA approved Egrifta (BLA 022505) on November 10, 2010 as a 1 mg vial. Egrifta SV, a 2 mg vial reconstituted with sterile water, carries a label revised March 2024. Egrifta WR, an 11.6 mg vial reconstituted with bacteriostatic water for a week of daily doses, carries a label dated March 2025 (Drugs@FDA supplement 020, action date March 25, 2025). The WR label states that Egrifta WR and Egrifta SV are not substitutable: the dose volumes, reconstitution and storage differ.

Because tesamorelin is the active ingredient of an approved drug, a 503A pharmacy may in principle compound with it when the other statutory conditions are met (a patient-specific prescription, no essentially-a-copy problem, and so on). A compounded tesamorelin is not Egrifta, has not been reviewed by FDA, and does not inherit the Egrifta label's stability data. The compounding site explains the "essentially a copy" limit.

Safety signals, from the label

Egrifta's Warnings and Precautions section, common to the SV and WR labels:

• Increased risk of neoplasms. Pre-existing malignancy should be inactive and its treatment complete before starting. Discontinue if malignancy develops.
• Fluid retention: oedema, arthralgia, carpal tunnel syndrome.
• Glucose intolerance or diabetes mellitus. Evaluate glucose before and during therapy.
• Hypersensitivity reactions, seen in clinical trials.
• Increased mortality in patients with acute critical illness.

Section 12.6 reports anti-tesamorelin IgG antibodies in 50% of patients at 26 weeks and 47% at 52 weeks with the 1 mg formulation. That number matters beyond tesamorelin: it is measured evidence that a well-manufactured, FDA-reviewed peptide provokes antibodies in half of recipients. FDA's immunogenicity concern for unreviewed peptides is not theoretical.

The adverse-reaction table in the label lists injection-site reactions, arthralgia, pain in extremity, myalgia, peripheral oedema, paraesthesia, hypoesthesia, rash and others at rates above placebo in 543 treated versus 263 placebo patients over 26 weeks.

Storage, per label

The three formulations differ, which is why the storage and handling guide walks through each. In brief: Egrifta SV vials are stored at room temperature, protected from light, reconstituted with 0.5 mL sterile water, used immediately, and the remainder discarded. Egrifta WR vials are stored at room temperature, reconstituted with 1.3 mL bacteriostatic water to 8 mg/mL, discarded 7 days after mixing, with the water bottle discarded 28 days after first use. If you have been prescribed one of these, the storage-life countdown counts down to the date on your label.

Grade: A

A for the labelled indication, because an FDA-approved product exists and FDA reviewed the trials. The grade does not extend to uses outside the label. A tesamorelin prescription for general fat loss is an off-label use of an approved drug, with a label that explicitly disclaims that use; a compounded "tesamorelin" from a research-chemical source is an unapproved drug that happens to share a name. Neither is graded A on this site.