At a glance: Tesamorelin is a lab-made version of growth-hormone-releasing hormone (GHRH). It is FDA-approved (Egrifta SV, Egrifta WR) for one use: reducing excess abdominal fat in adults with HIV-associated lipodystrophy. It is backed by randomized trials for that use, is prescription-only, and is not approved for general weight loss or bodybuilding.
What is tesamorelin?
Tesamorelin is a synthetic analog of growth-hormone-releasing hormone (GHRH), the brain hormone that tells the pituitary gland to release growth hormone. It contains the full 44-amino-acid GHRH sequence with a chemical modification at one end that makes it more resistant to breakdown, so it lasts longer in the body than natural GHRH.
It is made by Theratechnologies, a Canadian company. The FDA first approved it as Egrifta in 2010. It was later reformulated as Egrifta SV, and in March 2025 the FDA approved Egrifta WR, a newer formulation that is mixed once a week instead of daily. The formulations are not interchangeable.
How does tesamorelin work?
- Binds GHRH receptors on the pituitary gland, prompting it to release the body's own growth hormone
- Keeps natural pulses: growth hormone is released in bursts, as it normally would be, rather than as a constant level like injected growth hormone
- Raises IGF-1: growth hormone drives the liver and other tissues to make insulin-like growth factor 1, which doctors monitor during treatment
- Breaks down visceral fat: growth hormone acts on fat tissue, especially the deep belly fat around the organs
What the research shows
Unlike most peptides on this site, tesamorelin has been through large, placebo-controlled human trials.
| Study | Who was studied | Main finding |
|---|---|---|
| Phase 3 trial (Falutz et al.) | Adults with HIV and excess abdominal fat, 26 weeks | Visceral fat fell 10.9% on tesamorelin vs 0.6% on placebo |
| Pooled analysis of two phase 3 trials | About 800 adults with HIV-associated abdominal fat | 15.4% treatment effect on visceral fat at 26 weeks, plus improvements in waist size and body image |
| Liver-fat trial (Stanley et al., Lancet HIV 2019) | 61 adults with HIV and fatty liver disease, 12 months | Liver fat fell 37% from baseline vs placebo; fewer patients had fibrosis progression (10.5% vs 37.5%) |
| Cognition trial (Baker et al., 2012) | Older adults with and without mild cognitive impairment, 20 weeks | Modest improvements in executive function vs placebo |
Benefits fade after stopping: in trials, visceral fat largely returned when treatment ended.
Why it gets attention
- It is an approved drug, which gives it credibility that research peptides lack
- Targets visceral fat, the deep belly fat most linked to heart and metabolic disease
- Fatty liver research, an area with few treatment options
- Off-label interest for a smaller waist, lean mass and anti-aging, which goes beyond what it is approved and proven for
How it is given
Tesamorelin is a prescription injection given once daily under the skin of the abdomen, rotating injection sites. Egrifta SV is mixed fresh for each dose, while one vial of Egrifta WR is mixed once and used for a week. The dose and formulation are set by the prescriber according to the FDA label; this page does not provide dosing guidance.
What about side effects?
Because it is an approved drug, its side effects are well documented on the FDA label and in Mayo Clinic's drug information:
- Common: injection-site redness, swelling, pain, itching or bruising; joint and muscle pain or cramps; swelling of the hands and feet; and tingling or numbness
- Other reported effects: nausea, vomiting, heartburn, reduced appetite, trouble sleeping, tiredness and trouble concentrating
- Blood sugar: it can raise glucose and worsen insulin resistance, so glucose is monitored, especially in people with diabetes
- IGF-1 levels: raised IGF-1 is monitored with regular blood tests, because high levels over time are a theoretical cancer concern
- Carpal tunnel symptoms from fluid retention; joint pain or hand numbness should be reported
- Seek prompt care for: chest pain, a fast or irregular heartbeat, blurred vision, weakness or numbness in the limbs, or signs of a serious allergic reaction such as hives, facial or throat swelling and trouble breathing
- Antibodies: many patients develop antibodies to tesamorelin
It should not be used during pregnancy, in people with active cancer, in people allergic to mannitol (an ingredient), or in people whose pituitary function has been affected by pituitary surgery, tumors, head radiation or head injury. Mayo Clinic advises caution in people with diabetes, diabetic eye disease (retinopathy), swelling, carpal tunnel syndrome, lung disease, or a recent heart or stomach surgery or serious injury. Its safety in children has not been established.
Regulatory status
- FDA-approved as Egrifta SV and Egrifta WR to reduce excess abdominal fat in adults with HIV-associated lipodystrophy. It is not approved to treat general obesity, and its effect on long-term heart outcomes has not been established.
- Prescription only. Other uses, such as for physique or anti-aging, are off-label and have not been tested in large trials.
- Tesamorelin sold online as a "research peptide" is not the approved drug and has no quality guarantees.
- It is prohibited in sport at all times under the World Anti-Doping Agency's list, as a growth hormone releasing factor.
How it compares to other growth hormone peptides
| Tesamorelin | Sermorelin | CJC-1295 / Ipamorelin | |
|---|---|---|---|
| Type | GHRH analog (44 amino acids) | GHRH fragment (29 amino acids) | GHRH analog / ghrelin mimetic |
| Human evidence | Large randomized trials | Older studies; US product discontinued | Limited small studies |
| US status | FDA-approved for HIV-associated abdominal fat | No longer marketed as an approved drug | Not approved |
The bottom line
Tesamorelin is one of the few peptides in this space with solid human evidence: randomized trials show it reduces visceral fat in people with HIV, and a trial showed it lowers liver fat. But that evidence is specific to its approved use, results fade when it is stopped, and it requires monitoring of blood sugar and IGF-1. Using it for general fat loss or physique goals means going beyond what has been proven. It should only be used under a prescriber's care.
Frequently asked questions
What is Tesamorelin?
A stabilized version of growth-hormone-releasing hormone.
How is Tesamorelin taken?
Daily subcutaneous injection.
Is Tesamorelin FDA approved?
FDA-approved (prescription).
What has research shown about Tesamorelin?
- Reducing excess abdominal fat in people with HIV-associated lipodystrophy.
- Liver fat in people with HIV, in clinical trials.
What side effects have been reported?
- Injection site reactions (17%)
- Joint pain (13%)
- Pain in an arm or leg (6%)
- Muscle pain (6%)
- Swelling in the limbs (6%)
Serious or less common risks are listed in the Side Effects section above.
What is still unknown about its safety?
Side effects that are rare, or that only appear after many years of use, are still being tracked through post-marketing surveillance. Talk to a prescriber about your own risk.
References
- Mayo Clinic: Tesamorelin (subcutaneous route), description, precautions and side effects. View source
- EGRIFTA SV (tesamorelin) prescribing information, DailyMed. View source
- EGRIFTA WR (tesamorelin) prescribing information, DailyMed. View source
- Falutz J, et al. Effects of tesamorelin in HIV-infected patients with abdominal fat accumulation: randomized placebo-controlled trial. 2010. View source
- Pooled analysis of two phase 3 trials of tesamorelin on visceral fat. 2010. View source
- Stanley TL, et al. Effects of tesamorelin on non-alcoholic fatty liver disease in HIV: a randomised, double-blind, multicentre trial. Lancet HIV. 2019. View source
- Theratechnologies receives FDA approval for EGRIFTA WR (March 2025). View source
- World Anti-Doping Agency: 2026 Prohibited List. View source
- Rite Aid: Tesamorelin overview. View source