Tesamorelin is a peptide analog of growth hormone-releasing hormone (GHRH). Bodybuilders are interested in it for fat loss and recovery, because it causes the body to make more of its own growth hormone instead of taking growth hormone directly. In clinical trials, tesamorelin reduced visceral adipose tissue (VAT), the deep fat around the organs, by about 15% in 26 weeks (NATAP; Relias Media).
Those trials were done in adults with HIV, not in bodybuilders. So this page sticks to the doses the research actually used, what happened, and where the research stops. If you want the bigger picture first, we cover the full list of tesamorelin benefits, side effects and dosage in one place.
Quick Answer
- Dose used in the main trials: 2 mg, once a day, injected under the skin, for 26 weeks (NATAP; Relias Media).
- Dose in the prescribing information (Egrifta SV): 1.4 mg, once a day, under the skin of the belly (Drugs.com; RxList).
- Dose for bodybuilding: none. No trial has tested tesamorelin for bodybuilding or muscle gain in healthy adults.
As with everything on our site, this is for research education only, not advice on how to use it.
What Is Tesamorelin?
Tesamorelin is a synthetic, stabilized growth hormone-releasing hormone (GHRH) analog made of 44 amino acids (Drugs.com; RxList). It binds to GHRH receptors in the pituitary gland and stimulates the release of the body’s own growth hormone (GH).
Mechanism of Action
It stimulates the pituitary gland to release growth hormone. Growth hormone then tells the liver to make IGF-1, a hormone that supports growth and has a building (anabolic) effect on other tissues. In the main trial, IGF-1 went up 81% on tesamorelin, while it fell 5% on placebo (NATAP; Relias Media).
Through these hormones, it lowers fat, mainly visceral fat. Tesamorelin itself does not stay in the blood for long. Its half-life is about 8 minutes, which means half of it is gone from the blood in that time (Drugs.com; RxList).
Medical Versus Bodybuilding Use
- Medical use: Tesamorelin is the active ingredient in the prescription medicine Egrifta. It is used to reduce extra belly fat in adults with HIV who have lipodystrophy. It is not meant for weight loss (Drugs.com; RxList).
- Bodybuilding use (off-label): Some athletes and bodybuilders use it to try to lose fat while keeping or gaining muscle. This use has not been tested in clinical trials.
Metabolic Impact
- Visceral fat: goes down while it is being used.
- Blood fats: triglycerides went down in the main trial.
- Blood sugar: can go up in some people (see Side Effects).
- Muscle and recovery: not proven. The trials did not measure them as main results.
That mix is why tesamorelin gets attention for leaning out, and also why the evidence for bodybuilding use is thin.
Benefits Of Tesamorelin For Bodybuilders
Tesamorelin has a few possible benefits for bodybuilders who want to improve body composition. Keep in mind that most of the data comes from studies in adults with HIV-related lipodystrophy, so results may not be the same for everyone.
Fat Loss And Body Composition
Tesamorelin clearly reduces visceral fat, the deep belly fat that sits around the internal organs. In the two 26-week trials in the prescribing information, visceral fat was measured with CT scans:
| Trial (26 weeks) | Tesamorelin | Placebo |
|---|---|---|
| Study 1 | 18% less visceral fat | 2% more |
| Study 2 | 14% less visceral fat | 2% less |
People who kept taking it from week 26 to week 52 held on to the result, with a change of 0% in one study and a further 5% drop in the other. Lower belly fat can mean a trimmer midsection, but the trials did not measure stage or physique results.
Muscle And Recovery: What Is Proven
Tesamorelin raises GH and IGF-1, and both are growth-related hormones. That is why people link it with muscle and recovery. But the trials were set up to measure belly fat, not muscle or recovery, and they were done in adults with HIV. We could not find a published trial that tested tesamorelin for muscle building in healthy adults.
Metabolism And Blood Fats
The trials also tracked blood fats and, later, liver fat:
| What was measured | Tesamorelin | Placebo | Study |
|---|---|---|---|
| Triglycerides (a blood fat) | Down 50 mg/dL | Up 9 mg/dL | 26 weeks, 412 adults (NATAP; Relias Media) |
| Liver fat | Down 4.1 points more than placebo (a 37% relative drop) | Comparison group | 12 months, 61 adults with fatty liver (HIVinfo; i-Base) |
| Reached normal liver fat | 35% of people | 4% of people | Same 12-month trial |
The liver fat study was small, so its results still need larger studies to confirm them.
Caveats To Consider
- Most of the data comes from adults with HIV-related lipodystrophy, not from healthy athletes or bodybuilders.
- The results fade once it is stopped. In the trials, people switched to placebo after week 26 regained visceral fat: up 22% in one study and 16% in the other by week 52 (Drugs.com; RxList; aidsmap).
- Response and safety differ from person to person. Anyone thinking about it should speak to a qualified healthcare professional.
Overall, tesamorelin can lower stubborn deep belly fat while it is being used. It is not a magic bullet, and the research does not cover bodybuilding.
Dosage for Bodybuilders
There are two dose numbers you will see for tesamorelin, and they come from two different places. Neither one was tested in bodybuilders.
| Where the number comes from | Dose | How often | How it was given | How long | Who it was tested in |
|---|---|---|---|---|---|
| Main phase 3 trials | 2 mg | Once a day | Injection under the skin | 26 weeks, some continued to 52 | Adults with HIV and extra belly fat |
| Prescribing information (Egrifta SV) | 1.4 mg | Once a day | Injection under the skin of the belly | Not a fixed length | Adults with HIV and extra belly fat |
Sources: trials (NATAP; Relias Media); prescribing information (Drugs.com; RxList)
These are the doses used in research and listed for the prescription medicine. They are not recommendations.
Tesamorelin Dosage Per Day
Both the trials and the prescribing information use one injection a day. That can sound strange, since tesamorelin leaves the blood within minutes. The reason is that it works like a starter signal: it tells the pituitary gland to release growth hormone, and growth hormone then raises IGF-1.
The trials did not test splitting the dose, taking it every other day, or changing it over time.
Administration And Timing
- How: an injection under the skin (subcutaneous), once a day.
- Where: the prescribing information says the belly (abdomen), and to rotate injection sites to different areas of the belly to lower injection site reactions (Drugs.com; RxList).
- Form: the medicine comes as a powder that is mixed with the sterile water supplied in the pack before use (same sources).
- Time of day: the research did not test morning versus night, or before versus after meals.
Is The Dose Built Up Slowly?
No. The prescribing information lists one fixed daily dose and does not describe a slow build-up (titration) plan (Drugs.com; RxList). So titration plans found online are not based on this research.
Tracking Progress: What The Trials Measured
| What was tracked | How | Source |
|---|---|---|
| Visceral (deep belly) fat | CT scan of the belly | Prescribing information |
| IGF-1 | Blood test; the prescribing information says to monitor IGF-1 during use | Prescribing information |
| Blood sugar | Blood tests, including HbA1c (3-month average blood sugar) | Prescribing information |
| Triglycerides | Blood test | Main phase 3 trial |
Sources: Drugs.com; RxList; NATAP
What You May Hear vs What Research Shows
A lot of what is said about tesamorelin in gyms and forums goes well past what the studies tested. Here is a side-by-side look.
| What you may hear | What the research shows |
|---|---|
| “It builds muscle.” | The trials measured belly fat, not muscle building. We found no published trial in healthy adults that tested it for muscle. |
| “There is a bodybuilding dose.” | No trial has tested a bodybuilding dose. The only research doses are 2 mg a day (trials) and 1.4 mg a day (prescribing information). |
| “Run it in cycles.” | The trials did not test cycles. They ran for 26 weeks, and some people continued to 52 weeks. |
| “Start low and build up.” | The prescribing information uses one fixed daily dose with no build-up plan. |
| “The results stay after you stop.” | In the trials, belly fat came back within 26 weeks of switching to placebo. |
| “It is a weight-loss drug.” | It is not. Its medical use is reducing extra belly fat in adults with HIV. |
Sources: Drugs.com; RxList; NATAP; Relias Media
None of this means people do not use it this way. It means the evidence for bodybuilding use is missing, so any bodybuilding dose you see online is a guess, not research.
How Long the Trials Lasted, and What Happened After
You will often see people talk about a tesamorelin “cycle”. The trials did not test cycles. They gave one injection a day for 26 weeks, and then some people kept going to 52 weeks while others were switched to placebo.
The pattern is simple: the result showed up by week 26 and held while people kept taking it, but it faded once they stopped. In plain words, tesamorelin seemed to work only for as long as it was being used (Drugs.com; RxList; aidsmap).
Tesamorelin and Ipamorelin Blend: What Is Known
Blends of tesamorelin and ipamorelin are widely talked about online, but the research has not caught up. We could not find a published trial that tested the two together, so there is no research-based dose for a blend.
The two work through different signals. Tesamorelin copies GHRH, while ipamorelin works through the ghrelin receptor, the one used by a hunger hormone (Superpower). Both signals end up at the pituitary gland, and the difference between them is the main point of our tesamorelin vs ipamorelin comparison.
Side Effects
The known side effects come from the trials in adults with HIV. There is no research on safety in healthy adults who use it for bodybuilding.
Common Side Effects
These were the most common in the first 26 weeks:
| Side effect | Tesamorelin | Placebo |
|---|---|---|
| Injection site reaction (redness, irritation) | 17% | 6% |
| Joint pain | 13% | 11% |
| Muscle pain | 6% | 2% |
| Swelling of hands or feet (edema) | 6% | 2% |
| Pain in arms or legs | 6% | 5% |
| Tingling or numbness | 5% | 2% |
Rare but Serious Risks
- Higher blood sugar: 5% of people on tesamorelin reached an HbA1c (3-month average blood sugar) of 6.5% or higher, compared with 1% on placebo.
- Allergic (hypersensitivity) reactions: reported in 4% of people treated in the trials.
- IGF-1 levels: because tesamorelin raises IGF-1, the prescribing information says to monitor IGF-1 during use.
Who Should Not Use It
The prescribing information says tesamorelin should not be used by people who have (Drugs.com; RxList):
- Problems with the pituitary gland or the hormone system that controls it
- Active cancer
- A known allergy to tesamorelin
- Pregnancy
Is Tesamorelin Banned in Sport?
Yes. The 2026 World Anti-Doping Agency (WADA) Prohibited List names tesamorelin under growth hormone releasing factors, and this class is banned at all times, both in and out of competition (2026 Prohibited List, official Dutch publication; Finnish Center for Integrity in Sports). Athletes who are drug tested should keep this in mind.
Conclusion
Tesamorelin has solid trial data for one thing: lowering deep belly fat in adults with HIV, at 2 mg a day in the trials and 1.4 mg a day in the prescribing information. The fat came back once people stopped. There is no tested dose for bodybuilding, no proof it builds muscle, and it is banned in tested sport. If you are reading about it for fat loss, the two numbers above and the side effects table are the facts to keep in mind. For how it compares with other options, see our guide to tesamorelin vs ipamorelin.
Frequently Asked Questions
What dose of tesamorelin was used in the trials?
The main trials used 2 mg once a day, injected under the skin, for 26 weeks (NATAP; Relias Media).
How long does tesamorelin take to work?
The trials measured results at 26 weeks, when deep belly fat was 14% to 18% lower than at the start (Drugs.com; RxList).
Does tesamorelin build muscle?
There is no good evidence. The trials measured belly fat, not muscle, and none tested it for muscle building in healthy adults.
Is tesamorelin banned in sport?
Yes. It is named on the 2026 WADA Prohibited List and banned both in and out of competition (official Dutch publication; Finnish Center for Integrity in Sports).
Is Egrifta the same as tesamorelin?
Yes. Egrifta is the brand name of the prescription medicine that contains tesamorelin.
Disclaimer
This article is for research education only. It is not medical advice, and it does not recommend any drug, dose or product. The doses shown are the ones used in published trials and listed in the medicine’s prescribing information, not instructions for use.
Products sold online as research peptides are not approved medicines and are not intended for human or veterinary use. Please talk to a qualified healthcare professional before making any decision about your health.
Sources
- Drugs.com. Egrifta SV (tesamorelin) prescribing information.
- RxList. Egrifta SV (tesamorelin).
- NATAP. Tesamorelin phase 3 trial, NEJM 2007 (Falutz et al.).
- Relias Media. Therapeutic trial of growth hormone releasing factor in HIV patients.
- aidsmap. Tesamorelin safe and effective for fat accumulation in patients taking HIV treatment. February 2010.
- HIVinfo. Tesamorelin and liver fat in people with HIV.
- i-Base. Tesamorelin for NAFLD in people living with HIV (Lancet HIV, 2019).
- Netherlands Treaty Series. 2026 Prohibited List (amendment to the Anti-Doping Convention).
- Finnish Center for Integrity in Sports (SUEK). Doping agent classes and substances 2026.
- Superpower. Ipamorelin: a selective ghrelin receptor agonist.