Tesamorelin is a lab-made version of growth-hormone-releasing hormone, sold as Egrifta. The dose question has an unusually precise answer, because the labels state it to the hundredth of a milligram, and an unusually narrow one, because that dose was only ever tested in one group of people [1].
What tesamorelin did in those trials is covered in the Egrifta trials. This page stays on the dose: what each label states, why the numbers differ, and what the studies gave. Tesamorelin sits under the weight goal here, but only the brand product is covered.
Brand only: why there is no compounded version
Egrifta was approved in 2010 under a new drug application. On March 23, 2020, its approval was deemed a biologics license, and it appears on the FDA’s list of products that made that switch [8]. The FDA’s notice to compounders states that products in this transition are not eligible for the exemptions that allow pharmacies to compound drugs [9].
So the only lawful tesamorelin is the brand product, used as its label describes. The doses below are the labels’ and the trials’, and nothing on this page is a dose for anyone to take.
What the two labels state
Two Egrifta labels are current, and they give different numbers for the same daily treatment. The Egrifta WR label states a dose of 1.28 mg injected under the skin once daily, into the abdomen [1]. The Egrifta SV label states 1.4 mg once daily, also into the abdomen [2].
| Egrifta WR | Egrifta SV | |
|---|---|---|
| Powder per vial | 11.6 mg | 2 mg |
| Mixed with | 1.3 mL bacteriostatic water | 0.5 mL sterile water |
| Dose on the label | 1.28 mg (0.16 mL), once daily | 1.4 mg (0.35 mL), once daily |
| One vial lasts | 7 daily doses | 1 dose; the rest is discarded |
| Where injected | Abdomen, rotating sites | Abdomen, rotating sites |
Both labels say the same thing about switching: the two products differ in dose, vial count, mixing and storage, and they are not substitutable [1]. A reader who sees 1.28 mg in one place and 1.4 mg in another is looking at two formulations, not two dose levels.
Why the trials used 2 mg and the labels do not
Every trial that established tesamorelin’s effect used an older formulation that came as 1 mg vials, at a dose of 2 mg once daily. The labels explain how the newer numbers were reached. Blood levels after 1.28 mg of Egrifta WR, or 1.4 mg of Egrifta SV, were similar to those after 2 mg of the original product, so the trial results were carried over rather than repeated [1] [2].
The pharmacology is unusual. The WR label puts the absolute bioavailability of a 2 mg dose of the original product under the skin at less than 4%, and gives a half-life of about 11 minutes [1]. The peptide reaches the pituitary as a brief pulse. The effect the trials measured, a rise in IGF-1, comes from the growth hormone released downstream rather than from the peptide lingering in the blood.
What the trials gave, and what came of it
The dose-ranging trial compared 1 mg and 2 mg daily against placebo in 61 people with HIV and central fat gain, for 12 weeks [3]. IGF-1, the hormone growth hormone drives, rose 48% on 1 mg and 65% on 2 mg. Trunk fat fell 9.2% on 2 mg, a significant difference from placebo, while the fall in visceral fat did not reach significance at either dose.
That is where 2 mg came from. The two phase 3 trials then gave 2 mg daily or placebo to 806 people with HIV, randomized 2 to 1, for 26 weeks [4]. Visceral fat fell with a treatment effect of −15.4%, and IGF-1 rose by a mean of 108 ng/mL against a 7 ng/mL fall on placebo.
The same 2 mg dose ran for 12 months in a liver-fat trial of 61 people with HIV and fatty liver disease [5]. Liver fat fell by 4.1 percentage points more than on placebo, a 37% relative reduction, and 35% of the tesamorelin group ended below the 5% liver-fat level the trial required for entry, against 4% on placebo.
Doses tested outside HIV
Two trials gave tesamorelin to people without HIV, and neither turned into a labeled use. In 53 adults with type 2 diabetes, 1 mg or 2 mg daily for 12 weeks did not change insulin response, fasting glucose or HbA1c compared with placebo [6]. The trial measured safety in diabetes, not weight or fat.
In 152 adults aged 55 to 87, a trial of 1 mg injected nightly for 20 weeks raised IGF-1 by 117% and lowered percent body fat by 7.4% [7]. It was designed to test memory and thinking, and adverse events were reported by 68% on tesamorelin against 36% on placebo. It remains one trial, with no follow-on approval.
What the label says to watch
The label’s monitoring advice is where the dose meets the patient. It says to check IGF-1 during treatment, because the effects of a long-term rise are unknown, and to consider stopping if levels stay well above normal [1]. In the 26-week trials, 47% of people on tesamorelin had IGF-1 more than 2 standard deviations above the mean, and 36% more than 3.
It also says to check glucose before and during treatment, and to weigh continuing in anyone whose visceral fat has not fallen. The full adverse-event record, including injection-site reactions and swelling, is on tesamorelin side effects.
Mixing and injecting
The WR vial is mixed with 1.3 mL of the bacteriostatic water supplied, swirled rather than shaken, and kept at room temperature for up to 7 days [1]. The SV vial is mixed with 0.5 mL of sterile water and used at once [2]. What the two diluents are, and why one allows a week of doses and the other does not, is explained in bacteriostatic water for peptides.
For how tesamorelin's close relative sermorelin was dosed when it was an approved drug, and why the two are not interchangeable, see sermorelin dosage and tesamorelin vs sermorelin.