Tesamorelin reduces visceral fat, the fat that surrounds the organs inside the abdomen. In a large trial of 412 people it fell by 15.2 percent in 26 weeks, while in the placebo group it grew by 5 percent. After a year of use the fall reached 17.5 percent and waist circumference shrank by 3.4 cm on average. Fat under the skin and body weight stayed almost unchanged. If you want to know what tesamorelin does to the belly, below are the numbers from placebo-controlled clinical trials.
Which fat does tesamorelin act on?
Tesamorelin acts selectively on visceral fat and barely touches subcutaneous fat. Visceral fat lies deep in the abdomen, around the liver, intestines and pancreas. Subcutaneous fat is the layer you can pinch with your fingers.
In a pooled analysis of two phase 3 trials, visceral fat fell by 24 cm² on a CT cross-section of the abdomen. Abdominal subcutaneous fat changed by 2 cm² over the same time, which is practically nothing. Thanks to this selectivity, tesamorelin targets the fat hidden deep in the abdomen, around the organs.
Why does growth hormone burn belly fat?
Visceral fat and low growth hormone drive each other. A 2015 review in Growth Hormone and IGF Research describes how a large amount of visceral fat lowers growth hormone secretion. Less growth hormone means weaker fat burning in exactly this place, so visceral fat keeps growing.
Tesamorelin breaks this circle. It is an analogue of GHRH, the hormone the hypothalamus uses to tell the pituitary to release growth hormone. It increases the pulses of the body's own growth hormone without changing their natural rhythm. In the 2007 NEJM trial the level of IGF-1, the main messenger of growth hormone, rose by 81 percent.
How much belly fat was lost in the trials?
All the large trials measured visceral fat with computed tomography, so precisely, not on the scales. Below are the results of four placebo-controlled trials in order of publication.
| Trial | Who and for how long | Visceral fat |
|---|---|---|
| Falutz, NEJM 2007 | 412 people with HIV, 26 weeks | minus 15.2 percent against plus 5.0 percent on placebo |
| Falutz, JCEM 2010, two trials pooled | 806 people with HIV, 26 weeks | minus 24 cm² against plus 2 cm² on placebo |
| Makimura, JCEM 2012 | 60 people with abdominal obesity without HIV, 12 months | minus 16 cm² against plus 19 cm² on placebo |
| Stanley, JAMA 2014 | 50 people with HIV, 6 months | minus 34 cm² against plus 8 cm² on placebo |
In each of these trials the dose was 2 mg under the skin once a day. For most readers the 2012 trial matters most. It included people with abdominal obesity and reduced growth hormone secretion, but without HIV. The effect against placebo there was 35 cm² of visceral fat on the abdominal cross-section.
How long does tesamorelin take to work?
The registration trials assessed the result after 26 weeks, that is after half a year of daily injections. In the group that took tesamorelin for a whole year, the effect kept growing. After 52 weeks visceral fat was 35 cm² smaller, which is 17.5 percent less than at the start.
- 26 weeks: visceral fat 15.2 percent lower in the NEJM trial, waist 3 cm smaller against 1 cm on placebo.
- 52 weeks: visceral fat 17.5 percent lower, waist 3.4 cm smaller.
- 12 months without HIV: an effect of 35 cm² of visceral fat against placebo in the 2012 trial.
Participants also rated their own belly in questionnaires. After 26 weeks they worried less about how it looked, and both the participants and their doctors rated it better.
What else improved along with the belly?
The loss of visceral fat went hand in hand with better blood and liver results. In the NEJM trial triglycerides fell by 50 mg/dl, while on placebo they rose by 9 mg/dl. The ratio of total cholesterol to HDL, the good cholesterol, also improved.
The 2014 JAMA trial looked at liver fat. After six months its share fell by 2.0 percentage points, while on placebo it rose by 0.9 points. In people without HIV the level of CRP, a marker of inflammation, fell, and the wall of the carotid artery became 0.04 mm thinner.
In the 2014 trial fasting glucose rose by 7 mg/dl more than on placebo after two weeks. After six months there was no longer any difference. In the 2012 trial fasting glucose, two-hour glucose and glycated haemoglobin did not change.
Does tesamorelin make you lose weight?
Tesamorelin changes where the fat sits, not the number on the scales.
The Egrifta WR drug label describes its effect on body weight as neutral, and this is why the medicine is not meant for weight loss. In the first registration trial body weight fell by 0.4 kg against zero on placebo.
For you this means looking for the effect in centimetres around the waist, not in kilograms. If the goal is weight loss, the GLP-1 drugs have stronger data, as described in the article semaglutide, tirzepatide and retatrutide compared.
What happens after stopping?
The effect lasts as long as the injections continue. In the registration trials some people switched from tesamorelin to placebo after 26 weeks. Over the following half year their visceral fat grew by 24 to 25 cm². In people who kept taking tesamorelin it fell by a further 3 to 11 cm² over the same time.
The whole group of GHRH analogues works this way, because the pituitary returns to its previous rhythm of secretion. How tesamorelin compares with sermorelin, Mod GRF 1-29 and CJC-1295 is shown in the article on GHRH analogues in one table.
Where to buy tesamorelin?
The shop has tesamorelin 10 mg Genheal for 50 EUR, in stock. The pack contains a vial of freeze-dried powder and a separate ampoule of solvent. Everything about the molecule is collected on the tesamorelin page, and the story of its approval is told in the article tesamorelin, the only GHRH analogue approved as a medicine.
The dose of 2 mg a day comes from the label of the approved medicine and from clinical trials. The product in the shop is material for laboratory research, not a medicine, so choosing a dose is a matter for a doctor. How to prepare the solution from the vial is shown in the guide on how to reconstitute a peptide. Athletes are bound by the WADA ban all year round.
Frequently asked questions
Does tesamorelin reduce belly fat?
Yes, it reduces visceral fat around the organs. In a trial of 412 people it fell by 15.2 percent in 26 weeks, while on placebo it grew by 5 percent.
How long does tesamorelin take to show results?
The trials assessed the result after 26 weeks of daily use. After 52 weeks visceral fat was down by 17.5 percent and the waist was 3.4 cm smaller.
Does tesamorelin work in people without HIV?
In a 2012 trial of 60 people with abdominal obesity without HIV, tesamorelin reduced visceral fat by 35 cm² against placebo over 12 months.
Does tesamorelin lower body weight?
No, its effect on body weight is neutral. It changes where fat sits, so the effect shows in waist circumference, not on the scales.
What happens to the belly after stopping tesamorelin?
Visceral fat comes back. People switched to placebo after 26 weeks regained 24 to 25 cm² of visceral fat over the next half year.
How much does tesamorelin cost in the shop?
Tesamorelin 10 mg Genheal costs 50 EUR and is in stock.
Sources
- Falutz J, Allas S, Blot K et al. Metabolic effects of a growth hormone-releasing factor in patients with HIV. New England Journal of Medicine, 2007, 357(23): 2359-2370. https://doi.org/10.1056/NEJMoa072375
- Falutz J, Mamputu JC, Potvin D et al. 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. Journal of Clinical Endocrinology and Metabolism, 2010, 95(9): 4291-4304. https://doi.org/10.1210/jc.2010-0490
- Makimura H, Feldpausch MN, Rope AM et al. Metabolic effects of a growth hormone-releasing factor in obese subjects with reduced growth hormone secretion: a randomized controlled trial. Journal of Clinical Endocrinology and Metabolism, 2012, 97(12): 4769-4779. https://doi.org/10.1210/jc.2012-2794
- Stanley TL, Feldpausch MN, Oh J et al. Effect of tesamorelin on visceral fat and liver fat in HIV-infected patients with abdominal fat accumulation: a randomized clinical trial. JAMA, 2014, 312(4): 380-389. https://doi.org/10.1001/jama.2014.8334
- Stanley TL, Grinspoon SK. Effects of growth hormone-releasing hormone on visceral fat, metabolic, and cardiovascular indices in human studies. Growth Hormone and IGF Research, 2015, 25(2): 59-65. https://doi.org/10.1016/j.ghir.2014.12.005
- EGRIFTA WR (tesamorelin) for injection. Prescribing information, DailyMed, U.S. National Library of Medicine. https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=839334d3-8c1d-4c26-9036-2ab524a6ea75