An FDA-approved GHRH analog that shrinks visceral belly fat in people with HIV lipodystrophy. Not approved for weight loss.
Also called Egrifta, Egrifta SV, Egrifta WR, TH9507, Tesamorelin acetate
Tesamorelin is the full 44-amino-acid human growth hormone-releasing hormone with a small fatty acid chain bolted onto the front end so blood enzymes cannot break it down as fast. It tells the pituitary to release more of its own growth hormone. Sold as Egrifta, it is the only drug FDA has approved to reduce excess abdominal fat in adults with HIV and lipodystrophy, a fat redistribution caused by older HIV medicines.
The evidence is strong for that one use. In two phase 3 trials with 806 people, daily 2 mg injections cut visceral fat, the fat packed around the organs, by about 15% over 26 weeks, while fat under the skin and body weight barely moved. Triglycerides fell. When people stopped, the visceral fat came back within months. Smaller trials found it lowered liver fat: in a 2019 trial of 61 people with HIV and fatty liver, liver fat fell 37% relative to baseline. A 2012 trial in 152 older adults found better scores on executive function tests after 20 weeks.
The tradeoffs are real. Nearly half of patients developed antibodies to the drug, 47% had IGF-1 above the normal range after 26 weeks (more than 2 SDS, with 36% above 3 SDS), joint pain and swelling were common, and the risk of developing diabetes was about 3 times higher than on placebo. The label states it is not a weight-loss drug. The EU never approved it: the sponsor withdrew its application in 2012 after regulators signaled the benefit-risk balance was not shown.
What it binds to, and what happens inside the body after that, step by step.
Tesamorelin binds GHRH receptors on the pituitary and increases the pulsatile release of growth hormone, which raises IGF-1 and IGFBP-3. Growth hormone breaks down stored fat, and visceral fat responds more than fat under the skin, which is why waist size and organ fat fall while weight changes little. The hexenoyl group protects the front of the molecule from enzyme attack, but the drug is still cleared from blood within minutes; its effect lasts because the GH and IGF-1 changes last.
Human results and animal results are kept apart below. A result in rats tells you a mechanism is plausible. It does not tell you what happens in a person.
Two phase 3 RCTs (806 patients) and a 2026 meta-analysis of five RCTs show daily tesamorelin reduces visceral fat by roughly 15-18% and liver fat by about 4 percentage points in people with HIV, without lowering body weight or subcutaneous fat. Evidence outside HIV is limited to one RCT in older adults (better executive function, 7.4% less body fat) and small studies; it has never been tested as a general obesity drug.
412 adults with HIV and abdominal fat accumulation, 26 weeks, double-blind
Visceral fat fell 15.2% on tesamorelin vs a 5.0% rise on placebo; triglycerides fell 50 mg/dL; IGF-1 rose 81%.
Read the study806 adults with HIV on antiretroviral therapy, 26 weeks plus 26-week extension
Visceral fat fell 15.4% more than placebo at 26 weeks; patients who stayed on drug kept a 17.5% reduction at 52 weeks.
Read the study5 RCTs of tesamorelin vs placebo in adults with HIV
Visceral fat fell 27.7 cm2, liver fat 4.3 percentage points and lean mass rose 1.4 kg vs placebo; BMI and subcutaneous fat did not change.
Read the study61 adults with HIV and liver fat of 5% or more, 12 months
Liver fat fell 4.1 points more than placebo (37% relative reduction); 35% vs 4% reached normal liver fat.
Read the study152 adults aged 55-87 (66 with mild cognitive impairment), 20 weeks
Executive function improved vs placebo (P = .005); IGF-1 rose 117% and body fat fell 7.4%; adverse events in 68% vs 36%.
Read the study50 adults with HIV, 6 months
Visceral fat fell by 42 cm2 vs placebo and liver fat by 2.9 percentage points; fasting glucose rose at 2 weeks but not at 6 months.
Read the study73 adults with HIV and abdominal obesity, open-label, 6 months
Waist fell 2.7 cm more than standard care, but cognition did not differ between groups.
Read the studyNo preclinical studies are listed as key studies here. The human data above carries the evidence.
These are questions the published research has not answered.
Now regulated as a biologic: the 2025 Egrifta WR approval was a supplemental Biologics License Application. The label says it is not indicated for weight loss and that long-term cardiovascular safety has not been established. In the EU, Ferrer Internacional withdrew its marketing application in June 2012 after the CHMP indicated the data did not show a positive benefit-risk balance. Prohibited at all times under WADA S2.2.4 as a GHRH analog.
How much of Tesamorelin is left after a single dose
Simple first-order model from the published half-life. Real clearance varies with dose, route, kidney and liver function and formulation. This is not a dosing schedule.
This table records the doses that trials and approved labels used, with the source for each row. It is a record of research, not a recommendation, and it is open to free members.
Which symptoms are expected and which mean stop and get help: side effects and red flags.
Tap a claim to see what the studies found.
The label says it is not indicated for weight loss. In trials it cut visceral fat about 15% while body weight, BMI and fat under the skin barely changed.
In people with HIV lipodystrophy it reduced visceral fat, trunk fat and waist size without changing subcutaneous belly fat. That is the basis of its approval.
In the extension phase, people switched to placebo regained the visceral fat they had lost; those who stayed on drug kept it off.
A 152-person trial in older adults found better executive function after 20 weeks. A 2025 trial in people with HIV found no difference in cognition versus standard care.
Almost all trials enrolled people with HIV. The older-adult trial found 7.4% less body fat, but there is no obesity trial in the general population.
These pairings come up often. Almost none have been tested together in a trial, and the evidence note on each says so plainly.
Pairs a drug that shrinks visceral fat while sparing lean mass with a drug that cuts overall weight through appetite.
EvidenceNo trial has combined them. Both can affect glucose regulation in different directions, and no safety data exist for the pair.
Adds a ghrelin-receptor trigger to the GHRH signal to raise GH further.
EvidenceNever studied. Ipamorelin is unapproved, and stacking raises IGF-1, which already exceeds 3 SDS in about a third of patients on tesamorelin alone.
Egrifta WR: room temperature, 20 to 25 C (68 to 77 F), per the FDA label.
Egrifta WR: room temperature, 20 to 25 C; one vial covers 7 daily doses and is discarded 7 days after mixing.
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