# What does tesamorelin do? Updated October 17, 2026. Source: https://whatdoestesamorelindo.com/ ## Short answer Tesamorelin is a lab-made form of growth hormone-releasing hormone that signals the pituitary gland to release more of the body’s own growth hormone.[1] In the U.S. it is FDA-approved for one use: reducing excess abdominal fat in adults with HIV and lipodystrophy.[1] It is not approved for weight loss, muscle building or anti-aging.[1] ## Quick fit check If any of these apply, mention them in the assessment: - **You are pregnant or could become pregnant:** The label says not to use tesamorelin during pregnancy because it could harm the baby.[1] Raise this with the provider. - **You have active cancer or have had cancer in the past:** The label says not to use it with active cancer, and any past cancer should be inactive with treatment finished first.[1] A provider weighs the risk of it coming back.[1] - **You have a pituitary problem, or have had head radiation or a head injury:** The label lists pituitary tumors or surgery, head radiation and head injury as reasons not to use tesamorelin.[1] Raise this with the provider. - **You have diabetes or high blood sugar:** Tesamorelin can raise blood sugar, and the label calls for checking it before and during treatment.[1] People with diabetes also need regular checks for eye problems (retinopathy).[1] - **You do not have HIV:** The only approved use is reducing excess belly fat in adults with HIV and lipodystrophy, so other uses are off-label.[1] A provider decides whether any option fits you. ## Key facts - **What it is:** A growth hormone-releasing factor (GHRF) analog, made of the 44 amino acids of human GHRH plus a small added chain.[1] - **Approved use:** Reducing excess abdominal fat in adults with HIV and lipodystrophy.[1] It is not for weight loss and has a weight-neutral effect.[1] - **How it’s taken:** One injection under the skin of the belly each day.[1] The dose is 1.28 mg for EGRIFTA WR and 1.4 mg for EGRIFTA SV, and the two are not interchangeable.[1][2] - **Typical trial result:** After 26 weeks, deep belly (visceral) fat fell an average of 18% and 14% in two trials, versus a 2% rise and a 2% fall with placebo.[1] - **Common side effects:** Injection site reactions, joint pain, pain in the arms and legs, muscle pain and swelling of the arms, hands, legs or feet.[1] - **Who should not use it:** People with pituitary problems, head radiation or a head injury, active cancer, an allergy to tesamorelin, or a pregnancy.[1] ## What happened over time in the trials | Time on treatment | What the trials found | | --- | --- | | By week 13 | Some patients already had IGF-1 levels more than 2 standard deviations above average.[1] | | Week 26 | Visceral fat was down an average of 18% and 14% in the two main trials, versus a 2% rise and a 2% fall with placebo.[1] | | Week 52, still taking it | The drop held, at about 17.5% below the starting level.[4] | | Week 52, stopped at week 26 | Visceral fat came back, rising 22% and 16% in the 26 weeks after switching to placebo.[1] | ## How it works - **It signals the pituitary:** In lab tests, tesamorelin binds the same receptors as the body’s own growth hormone-releasing hormone, with similar potency.[1] That signal prompts the pituitary gland to release growth hormone in pulses.[1] - **Growth hormone raises IGF-1:** The extra growth hormone then raises IGF-1 and IGFBP-3 levels.[1] IGF-1 carries out some, but not all, of growth hormone’s effects.[1] - **It targets deep belly fat:** Growth hormone both breaks down fat and builds tissue.[1] In the main trials, tesamorelin lowered visceral fat without a significant change in the fat just under the skin of the belly.[4] - **Other hormones:** Trials found no clinically significant changes in other pituitary hormones, such as thyroid-stimulating hormone or prolactin.[1] - **It acts briefly:** Tesamorelin peaks in the blood within minutes of an injection and has a half-life of about 11 minutes.[1] ## What the evidence shows - **Belly fat in adults with HIV:** In many people with HIV, visceral fat builds up during antiretroviral therapy.[3] In two 26-week placebo-controlled trials in this group, tesamorelin cut visceral fat by an average of 18% and 14% on CT scans.[1] - **Waist size and weight:** Waist size shrank by about 1 to 2 cm more than with placebo, while average body weight changed by less than 1 kg.[1] - **Blood fats:** In one of the two main trials, triglycerides fell by 50 mg/dL with tesamorelin and rose by 9 mg/dL with placebo.[3] - **Results fade after stopping:** People who kept taking it for a full year held their visceral fat loss.[4] People switched to placebo after 26 weeks regained visceral fat over the next 26 weeks.[1] - **If fat does not go down:** The label advises weighing whether to continue treatment in people whose visceral fat has not gone down.[1] - **People without HIV (off-label):** One 12-month trial gave tesamorelin or placebo to 60 adults with abdominal obesity and low growth hormone output, and it excluded people with HIV.[5] Visceral fat shrank with tesamorelin and grew with placebo, with no change in fasting glucose or HbA1c.[5] This is not an approved use.[1] - **Liver fat (still being studied):** In a 6-month trial of 50 adults with HIV, tesamorelin was linked to modest reductions in liver fat, and the authors said further studies are needed.[6] - **Muscle and anti-aging (off-label):** Tesamorelin is not approved to build muscle or slow aging.[1] The label has no information on its use in people over 65.[1] ## Side effects and who should avoid it - **Most common:** In the first 26 weeks of trials, injection site reactions affected 25% of people on tesamorelin and 14% on placebo.[1] Joint pain (13% vs 11%), muscle pain (6% vs 2%) and swelling in the arms or legs (6% vs 2%) were also more common.[1] - **Blood sugar:** Tesamorelin can cause glucose intolerance.[1] In trials, 5% of people on it reached an HbA1c of 6.5% or higher, compared with 1% on placebo.[1] The label calls for checking blood sugar before and during treatment.[1] - **Raised IGF-1:** The long-term effects of high IGF-1 levels are unknown.[1] The label calls for monitoring IGF-1 during treatment.[1] - **Fluid retention:** It can cause swelling, joint pain and carpal tunnel syndrome, which either pass on their own or go away after stopping.[1] - **Cancer:** Because it raises growth hormone, a known growth factor, it must not be used with active cancer.[1] It should be stopped if there is any sign that a past cancer has come back.[1] - **Do not use if you:** Have a pituitary tumor, pituitary surgery or other pituitary problem, have had head radiation or a head injury, have active cancer, are allergic to tesamorelin, or are pregnant.[1] It is not for children.[1] - **Other medicines:** People on glucocorticoid replacement for adrenal insufficiency may need a higher dose after starting tesamorelin.[1] Tell your provider about every medicine and supplement you take.[1] ## When to get medical help - **Signs of a serious allergic reaction:** A rash over your body, hives, swelling of the face or throat, trouble breathing, a fast heartbeat or fainting. Stop tesamorelin and get emergency help right away.[1] - **Cancer symptoms come back:** Stop using tesamorelin and tell your provider.[1] - **Swelling, joint pain, or numbness in the hands or wrists:** Call your healthcare provider.[1] - **Problems at the injection site:** Redness, itching, pain, bruising, bleeding, rash or swelling around the injection. Call your provider and keep rotating injection sites.[1] - **Pregnancy:** If you become pregnant, stop using tesamorelin and talk with your provider.[1] It could harm the baby.[1] ## Common questions ### Does tesamorelin build muscle? It is not approved for that.[1] In the HIV trials, lean body mass rose by about 1.2 to 1.3 kg over 26 weeks, compared with almost no change on placebo.[1] In another trial, the authors noted that part of a similar gain might reflect fluid and water shifts.[5] ### Does tesamorelin reduce belly fat in people without HIV? It is only approved for adults with HIV and lipodystrophy.[1] A 12-month trial in 60 adults with abdominal obesity and low growth hormone output, which excluded people with HIV, found that visceral fat shrank with tesamorelin and grew with placebo.[5] Using it this way is off-label.[1] ### How long does tesamorelin take to work? The main trials judged results after 26 weeks of daily injections.[1] In people who kept taking it, the drop in visceral fat lasted through 52 weeks.[4] In people who stopped at 26 weeks, the fat came back.[1] ### Is tesamorelin a steroid or HGH? Neither. It is a peptide built on the 44 amino acids of human growth hormone-releasing hormone.[1] It is not growth hormone itself.[1] It prompts the pituitary to release the body’s own growth hormone.[1] ### Will tesamorelin help me lose weight? No. The label says it is not for weight loss because its effect on weight is neutral.[1] In trials, average body weight changed by less than 1 kg.[1] ### What is the difference between tesamorelin and sermorelin? Both are versions of growth hormone-releasing hormone.[1][7] Sermorelin is a shorter, 29-amino-acid version.[7] Its U.S. brand was approved for children with growth hormone deficiency and was discontinued, with FDA later finding this was not for safety or effectiveness reasons.[8] Tesamorelin uses the full 44-amino-acid chain and is approved only for abdominal fat in adults with HIV and lipodystrophy.[1] ## Next step **Find out if tesamorelin is right for you.** Complete an online health assessment. A licensed provider reviews it and decides whether tesamorelin or another option is appropriate. What the assessment includes: - Online health assessment - Review by a licensed provider - Shipped to you if prescribed - Card held at checkout, charged only if prescribed How to get started: 1. **Answer health questions.** An online assessment about your health, history and goals. 2. **A licensed provider reviews it.** They decide whether a prescription is safe and appropriate for you. 3. **If prescribed, it ships to you.** Your card is only held at checkout. You’re charged only if a provider prescribes. Not everyone qualifies. A provider decides based on your health history. Start the assessment: https://whatdoestesamorelindo.com/go/md/agent Assessments are completed with a partner telehealth provider. This site may earn a commission if you start one through it. ## Sources 1. EGRIFTA WR (tesamorelin) for injection, full prescribing information. Theratechnologies, via U.S. Food and Drug Administration. Revised March 2025. https://www.accessdata.fda.gov/drugsatfda_docs/label/2025/022505s020lbl.pdf 2. EGRIFTA SV (tesamorelin) kit, drug label information. Theratechnologies, via DailyMed, U.S. National Library of Medicine. Revised February 2024. https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=3d783378-b02d-4f19-99dd-0fc91a042224 3. Metabolic effects of a growth hormone-releasing factor in patients with HIV. Falutz J, et al. New England Journal of Medicine. December 2007. https://pubmed.ncbi.nlm.nih.gov/18057338/ 4. Effects of tesamorelin (TH9507), a growth hormone-releasing factor analog, in HIV-infected patients with excess abdominal fat: a pooled analysis of two phase 3 trials with safety extension data. Falutz J, et al. Journal of Clinical Endocrinology and Metabolism. September 2010. https://pubmed.ncbi.nlm.nih.gov/20554713/ 5. Metabolic effects of a growth hormone-releasing factor in obese subjects with reduced growth hormone secretion: a randomized controlled trial. Makimura H, et al. Journal of Clinical Endocrinology and Metabolism. December 2012. https://pmc.ncbi.nlm.nih.gov/articles/PMC3513535/ 6. Effect of tesamorelin on visceral fat and liver fat in HIV-infected patients with abdominal fat accumulation: a randomized clinical trial. Stanley TL, et al. JAMA. July 2014. https://pubmed.ncbi.nlm.nih.gov/25038357/ 7. Sermorelin: a review of its use in the diagnosis and treatment of children with idiopathic growth hormone deficiency. Prakash A, Goa KL. BioDrugs. August 1999. https://pubmed.ncbi.nlm.nih.gov/18031173/ 8. Determination that GEREF (sermorelin acetate) injection was not withdrawn from sale for reasons of safety or effectiveness. U.S. Food and Drug Administration, Federal Register. March 4, 2013. https://www.federalregister.gov/documents/2013/03/04/2013-04827/determination-that-geref-sermorelin-acetate-injection-05-milligrams-basevial-and-10-milligrams --- General education, not medical advice. Talk to a licensed clinician before starting or changing any medicine.