Underground Biohacking
Growth hormone

Tesamorelin

Chris Hallewell, founder of Underground Biohacking

By , Founder, Underground Biohacking

Last reviewed

FDA-approved prescription (HIV lipodystrophy)

Tesamorelin is an approved prescription medicine, not a research chemical. The FDA cleared it in 2010 under the brand Egrifta. Its approval covers one narrow job: cutting excess belly fat in adults with HIV. Those patients have lipodystrophy (a condition that changes where the body stores fat). The label states it is not approved for weight loss. Inside that group the human evidence is strong, with large placebo controlled trials. Outside HIV, the evidence is much thinner.

What is Tesamorelin?

Tesamorelin is a synthetic copy of growth hormone releasing factor, or GRF. GRF is a peptide made in the hypothalamus, a control centre deep in the brain. Tesamorelin carries the same 44 amino acid sequence as the human hormone. A short carbon chain is attached at one end, and that is the only structural difference. That structure is the whole point. Tesamorelin does not put growth hormone into your body. It binds the same receptors as your own GRF, on cells in the pituitary gland. Those cells then release your own growth hormone in pulses, the way they normally would. Growth hormone then raises IGF-1, a growth factor made mostly in the liver. So tesamorelin belongs to a class called GRF analogues. It is not a supplement and it is not a research chemical. It is a prescription injection, sold as Egrifta, and it has been through full FDA review. Doctors prescribe it for one approved use, which the sections below explain.

What is Tesamorelin prescribed for?

  • In people with HIV and abdominal fat gain, treatment cut visceral fat (the deep fat around the organs) and improved blood fats.[1]Human study
  • In two pooled phase 3 trials in people with HIV, the fat loss held for a year and body image scores improved.[3]Human study
  • In people with HIV and fatty liver disease, a placebo controlled trial found less liver fat and no worsening of scarring.[8]Human study
  • In people with HIV taking integrase inhibitor drugs, body composition improved without worsening blood sugar control.[9]Human study
  • In older adults with and without mild cognitive impairment, thinking test scores improved in a placebo controlled trial.[6]Human study
  • In people with HIV and excess belly fat, markers of clotting and fat tissue health improved modestly.[4]Human study
  • In a later trial in people with HIV, waist size fell but thinking scores did not beat usual care.[10]Human study

How does Tesamorelin work?

Tesamorelin is a lab made copy of the full 44 amino acid GHRH molecule, your growth hormone releasing hormone. A small fat like tag, called a hexenoyl group, sits on the tyrosine at one end. That tag makes the peptide more stable than the natural hormone. The rest behaves like the hormone it copies. It binds the same GHRH receptor with much the same strength. Your pituitary gland then makes and releases its own growth hormone in pulses. Growth hormone lifts IGF-1, and IGF-1 carries out many of its effects. Tesamorelin is given as an injection under the skin.

Educational reference only. Talk to a licensed clinician for any decisions on Tesamorelin.

What are the side effects of Tesamorelin?

EffectHow seriousWhat to watch
Injection site complaints, such as redness and itching, were more common than with placebo.[7]Mild, none judged serious in that trialSkin at the injection sites, reported to the prescribing doctor
Joint pain, headache and fluid swelling were reported, which are known growth hormone effects.[5]Mild to moderateNew joint pain, headaches, or puffy hands and ankles
Overall side effect rates matched placebo, but more treated patients dropped out because of one.[1]UnknownAny new symptom bad enough to make you want to stop
Blood sugar is the main safety worry, though trials found no clear worsening.[9]Unknown over the long termFasting glucose and HbA1c, checked by a doctor
The benefit reverses. Visceral fat came back once treatment stopped.[2]Not harmful, but the gain is lostWaist size and blood fats after stopping

Is Tesamorelin legal in 2026?

Checked on 6 August 2026. Tesamorelin is an FDA approved medicine, not an unapproved research peptide. The FDA approved it on 10 November 2010 under application 022505, held by Theratechnologies. That application was later deemed a biologic licence. The current prescribing information says the medicine is indicated for the reduction of excess abdominal fat in HIV infected adult patients with lipodystrophy. The same label sets out limits of use. It is not indicated for weight loss management. Long term cardiovascular safety has not been established. So the approval covers one population, not general fat loss, and the medicine is prescription only.

Status checked against the primary source.

Educational reference only. Talk to a licensed clinician for any decisions on Tesamorelin.

If you are considering Tesamorelin

This page does not provide dosing, cycling, stacking, or sourcing guidance for Tesamorelin. The protocol conversation belongs with a licensed clinician who can review your bloodwork, history, and goals.

Where to buy Tesamorelin

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Frequently Asked Questions

What is tesamorelin actually approved for?
It has one approved use in the United States. The FDA cleared it to reduce excess abdominal fat in adults with HIV who have lipodystrophy. That is the whole approved scope. The label also spells out three limits on that use. It is not approved for weight loss management. Long term heart safety has not been established. And there is no evidence it helps people stay on their HIV medicines.
Does it work for general fat loss?
That has not been shown. The approval does not cover it, and the label states the medicine is not indicated for weight loss management. The trials behind the approval ran in people with HIV who had a specific pattern of fat gain. Those results do not simply transfer to a healthy person who wants to be leaner. Nobody has run the large trial that would answer the question properly.
What did the liver studies show?
One placebo controlled trial ran for a year in people with HIV and fatty liver. Liver fat fell more in the treated group than in the placebo group. A follow up analysis of the same trial found it also stopped scarring from getting worse. Fasting glucose and HbA1c did not differ between the groups. This is real human evidence, but it is one trial in one population. Longer studies have not been done.
Does it help memory or thinking?
The evidence points both ways. A placebo controlled trial in older adults, some with mild cognitive impairment, found better thinking scores after 20 weeks. A later trial in people with HIV and belly fat found waist size fell, but thinking scores did not beat usual care. That trial was small and had no placebo group. So the cognitive claim is unsettled. No trial has been large enough to settle it.
What are the main risks?
The prescribing information carries several warnings. The medicine raises IGF-1, and the effect of keeping IGF-1 high for years is unknown. Fluid retention can cause swelling, joint pain and carpal tunnel symptoms. Blood sugar can drift towards diabetes, so glucose is checked before and during treatment. The label warns about new growths, and it is not given to people with active cancer. Injection site and allergic reactions also occur.
What should I ask a doctor about it?
Start with whether you fit the approved use, since that is the only setting with strong evidence. Ask what your blood sugar and IGF-1 look like now, and how often they would be rechecked. Ask about your own cancer history, because active cancer rules the medicine out. Ask what happens when treatment stops, since the fat came back in the trials. And ask what the alternatives are.

References

  1. 1.Falutz J, et al. (2007). Metabolic effects of a growth hormone-releasing factor in patients with HIV. The New England journal of medicine. PMID: 18057338. DOI: 10.1056/NEJMoa072375.
  2. 2.Falutz J, et al. (2008). Long-term safety and effects of tesamorelin, a growth hormone-releasing factor analogue, in HIV patients with abdominal fat accumulation. AIDS (London, England). PMID: 18690162. DOI: 10.1097/QAD.0b013e32830a5058.
  3. 3.Falutz J, et al. (2010). Effects of tesamorelin (TH9507), a growth hormone-releasing factor analog, in human immunodeficiency virus-infected patients with excess abdominal fat: a pooled analysis of two multicenter, double-blind placebo-controlled phase 3 trials with safety extension data. The Journal of clinical endocrinology and metabolism. PMID: 20554713. DOI: 10.1210/jc.2010-0490.
  4. 4.Stanley TL, et al. (2011). Effects of tesamorelin on inflammatory markers in HIV patients with excess abdominal fat: relationship with visceral adipose reduction. AIDS (London, England). PMID: 21516030. DOI: 10.1097/QAD.0b013e328347f3f1.
  5. 5.Dhillon S (2011). Tesamorelin: a review of its use in the management of HIV-associated lipodystrophy. Drugs. PMID: 21668043. DOI: 10.2165/11202240-000000000-00000.
  6. 6.Baker LD, et al. (2012). Effects of growth hormone–releasing hormone on cognitive function in adults with mild cognitive impairment and healthy older adults: results of a controlled trial. Archives of neurology. PMID: 22869065. DOI: 10.1001/archneurol.2012.1970.
  7. 7.Stanley TL, et al. (2019). Effects of tesamorelin on non-alcoholic fatty liver disease in HIV: a randomised, double-blind, multicentre trial. The lancet. HIV. PMID: 31611038. DOI: 10.1016/S2352-3018(19)30338-8.
  8. 8.Fourman LT, et al. (2020). Effects of tesamorelin on hepatic transcriptomic signatures in HIV-associated NAFLD. JCI insight. PMID: 32701508. DOI: 10.1172/jci.insight.140134.
  9. 9.Russo SC, et al. (2024). Efficacy and safety of tesamorelin in people with HIV on integrase inhibitors. AIDS (London, England). PMID: 38905488. DOI: 10.1097/QAD.0000000000003965.
  10. 10.Ellis RJ, et al. (2025). Effects of Tesamorelin on Neurocognitive Impairment in Persons With HIV and Abdominal Obesity. The Journal of infectious diseases. PMID: 39813152. DOI: 10.1093/infdis/jiaf012.

One more time, because it matters

This page exists to identify Tesamorelin and explain what the research describes. Underground Biohacking does not advise on dosage, cycling, stacking, or where to source prescription compounds. If Tesamorelin is part of your plan, that conversation belongs with a clinician who can review your labs, history, and goals. Not with a website.