What it is
Tesamorelin is a stabilized growth hormone releasing hormone (GHRH) analog. It is FDA-approved, under the brand name Egrifta, to reduce excess visceral abdominal fat in HIV-associated lipodystrophy, and it has also been studied for visceral fat reduction more broadly.
In the PeptidesAI encyclopedia it is categorized under both growth hormone and weight management, reflecting that its approved use and its broader research both center on body composition rather than growth hormone deficiency alone.
How it's thought to work
Tesamorelin is studied for stimulating pulsatile growth hormone release from the pituitary gland, which elevates IGF-1 (insulin-like growth factor 1) and is described as preferentially mobilizing visceral adipose tissue, the fat stored around internal organs, over other fat deposits such as subcutaneous fat. Visceral fat is specifically implicated in metabolic risk, which is part of why reducing it, rather than fat in general, has been the focus of tesamorelin's approved use and broader research.
What the research says
Multiple clinical trials support visceral fat reduction associated with tesamorelin, and on that basis the FDA has approved it as Egrifta specifically for HIV-associated lipodystrophy. Use for visceral fat reduction outside that approved population is not FDA-approved, even though the underlying mechanism is the same.
Reported side effects
Reported side effects include injection site reactions, joint pain, fluid retention, tingling in the extremities, and elevated blood sugar. Because of the blood sugar effect, monitoring of blood glucose and IGF-1 levels is recommended.
Reconstitution
Tesamorelin is supplied as a lyophilized (freeze-dried) powder and is typically reconstituted with bacteriostatic (BAC) water before use. It commonly comes in 2 mg, 5 mg and 10 mg vials. The amount of peptide in the vial is fixed; the water added only changes how concentrated the solution is.
Worked example. A 5 mg vial is 5,000 mcg. Reconstituted with 2 mL of BAC water, that works out to 5,000 mcg ÷ 2 mL = 2,500 mcg/mL. On a U-100 insulin syringe, where each unit is 0.01 mL, each unit holds 2,500 × 0.01 = 25 mcg. A 2 mg vial with 1 mL comes out at 2,000 mcg/mL instead, or 20 mcg per unit. Use the peptide reconstitution calculator to work out the concentration and units for any vial size and water volume.
Important notes
Tesamorelin is FDA-approved for a specific indication, HIV-associated lipodystrophy; off-label use for other purposes is not FDA-approved. Blood sugar should be monitored given its reported effect on glucose levels, alongside periodic checks of IGF-1.
Frequently asked questions
These questions cover the same ground as the sections above, in a shorter format.
What is tesamorelin?
A stabilized GHRH analog, FDA-approved as Egrifta to reduce excess visceral abdominal fat in HIV-associated lipodystrophy.
How is tesamorelin thought to work?
It stimulates pulsatile growth hormone release, raising IGF-1 and preferentially mobilizing visceral fat around internal organs.
What does the research on tesamorelin say?
Multiple clinical trials support visceral fat reduction, which led to FDA approval as Egrifta for HIV-associated lipodystrophy; other uses are off-label.
What are the reported side effects of tesamorelin?
Injection site reactions, joint pain, fluid retention, tingling in the extremities, and elevated blood sugar, which warrants glucose monitoring.
How much is one unit from a 5 mg Tesamorelin vial?
With 2 mL of BAC water, a 5 mg vial is 2,500 mcg/mL, so one unit on a U-100 syringe (0.01 mL) holds 25 mcg.
The full entry, plus the calculator
The PeptidesAI app has the complete encyclopedia entry for Tesamorelin — one of 70 compounds covered — plus the reconstitution calculator, a dose log and reminders. Free to download on iPhone.
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