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Tesamorelin: what happened to the people studied?
Tesamorelin prompts your growth gland to release more hormone. You'll learn who received it, what researchers measured, and which questions remain open for you.
What is tesamorelin, and whom can it help?
Tesamorelin is a man-made drug that prompts the body to release growth hormone; this page explains what study results may mean for you before you speak with your doctor.
The pituitary, or growth gland, sits below the brain, where a brain hormone normally tells it when to release growth hormone. Tesamorelin gives your gland a version of that order that lasts longer.
Growth hormone then asks the liver to make insulin-like growth factor 1, a blood protein that carries growth orders to body tissues. Together, these hormones helped people use fat buried deep in the belly.
The FDA cleared tesamorelin only for unusual belly-fat buildup linked to HIV. Doctors use “off-label” for any other use because the FDA hasn't cleared it.
What is in tesamorelin, and who was studied?
Tesamorelin is a 44-amino-acid medicine, and amino acids are small protein parts; its first part was changed so the body's protein-cutting chemicals take longer to break the drug apart, giving it more time to reach the growth gland.
The clearest proof comes from people with HIV whose bodies stored fat in unusual places. Two Phase 3 studies were large checks before approval [1][2], and a smaller Phase 2 study tested several amounts earlier [7]. Other work measured liver fat [3] or followed healthy men [4]. Two studies watched the drug in blood and followed the later hormone response [8][9]. In 2026, reviewers combined five trials that included comparison groups [12].
These pages tell you what happened to the people studied. The site doesn't sell tesamorelin or tell you to use it; supplies marked for laboratory study aren't medicine to keep at home.
How did tesamorelin change belly fat in the main studies?
The strongest 26-week Phase 3 study followed 412 people with HIV. People given 2 milligrams of tesamorelin each day lost 15.2% of the fat deep around their organs, while those given a placebo shot gained 5.0% [1]. Triglycerides are fats found in a blood test. That result fell 50 milligrams per deciliter with tesamorelin but rose 9 milligrams per deciliter with placebo. A deciliter is one-tenth of a liter. Growth factor 1, the liver-made growth protein, rose 81.0% [1].
A 52-week study asked whether the early fat loss lasted, and deep belly fat remained 18% lower [2]. In an earlier 12-week test, growth factor 1 rose 48% with 1 milligram each day. It rose 65% with 2 milligrams each day, compared with placebo [7].
A 2026 review combined five trials with comparison groups. Scans showed a drop averaging 27.71 square centimeters of deep belly fat, which is an area inside the belly rather than inches lost from your waist. A 95% check asks whether chance could explain the result; here, the answer still favored a real loss rather than a gain. Fat across the chest and belly fell too. Liver fat fell, while muscle, bone, water, and organs taken together rose [12]. The review couldn't show how much of that gain was muscle.
The limits may shape your choice. Tesamorelin barely changed fat under the skin or scale weight [1], and deep fat started coming back a few weeks after treatment ended [2]. All participants had the fat problem linked to HIV. The findings don't prove general weight loss for you or anyone without that problem.
What is tesamorelin used for under FDA approval?
What is tesamorelin used for?
For adults who have both HIV and lipodystrophy, the FDA cleared tesamorelin to reduce extra belly fat [5]. Lipodystrophy means fat has moved to unusual parts of the body, sometimes after HIV drugs. The approval doesn't include slowing aging, changing looks, boosting hormones, or treating fatty liver unrelated to HIV.
Is tesamorelin FDA approved?
Yes, for that single use approved in the United States in 2010 [5]. People without HIV and lipodystrophy aren't covered by the approval. A drug can be approved yet not approved for your illness. Read whether tesamorelin has FDA approval for your case for more.
Which page answers your next tesamorelin question?
Tesamorelin disappears from blood quickly, while growth factor 1 lasts much longer. One study listed a clearance rate of 1,060 liters each hour [8]. That isn't your blood volume. Researchers compared the dose with the tiny amount found in blood, then expressed the speed as an imagined volume cleared of drug. Another study showed that the brief visit still started hormone bursts that kept growth factor 1 high [9]. The page about time in blood joins those two findings.
Read how tesamorelin gives the growth gland its order and see what belly scans showed. You can also compare tesamorelin and sermorelin, review amounts used by researchers, or check harms and reasons to avoid treatment. The complete study list names the paper for each figure.
Start with your own question, then choose the page that answers it.