Tesamorelin is a lab-made version of growth-hormone-releasing hormone (GHRH), modified so it survives longer in the body. It prompts the pituitary gland to release more of the body’s own growth hormone. Developed by Theratechnologies of Montreal, it’s one of the few “research peptides” that is also an approved drug: Egrifta, approved by the FDA in 2010 and by Health Canada on April 30, 2014, to reduce excess abdominal fat in people living with HIV.
In the phase 3 trials, it cut visceral (deep belly) fat by about 15% in six months, with little change in overall weight. Later trials showed reductions in liver fat, and an intriguing study found improved executive function in older adults. This guide covers all of it, plus the side effects and how it compares to CJC-1295 and ipamorelin.
What tesamorelin is
Tesamorelin (development code TH9507) is a 44-amino-acid peptide with the same sequence as human GHRH, the hormone the hypothalamus uses to tell the pituitary to release growth hormone. The one change is a small chemical group (a trans-3-hexenoyl group) attached to the first amino acid.
That small change matters. Natural GHRH is broken down within minutes, mainly by an enzyme called DPP-4, the same enzyme that degrades GLP-1. The modification protects tesamorelin from that enzyme, so it lasts long enough to work as a daily drug while still acting through the body’s normal control system.
| Property | Detail |
|---|---|
| Class | GHRH analogue (growth hormone secretagogue) |
| Length | 44 amino acids |
| Developer | Theratechnologies Inc., Montreal |
| Brand name | Egrifta (later Egrifta SV and Egrifta WR formulations) |
| FDA approval | November 2010 |
| Health Canada approval | April 30, 2014 |
| Approved use | Reducing excess abdominal fat in adults with HIV and lipodystrophy |
How it works: the GH axis in plain English
Growth hormone release is controlled by a chain of signals:
- The hypothalamus releases GHRH (the “go” signal) and somatostatin (the “stop” signal).
- The pituitary responds to GHRH by releasing growth hormone in pulses, mostly at night.
- Growth hormone acts on tissues directly, including fat, where it promotes fat breakdown, and on the liver, which responds by making IGF-1.
- IGF-1 and GH feed back to the hypothalamus and pituitary to dampen further release.
Tesamorelin enters at step 1. Because it works through the pituitary instead of replacing growth hormone, the feedback loop stays intact. GH is still released in pulses, and somatostatin can still apply the brakes. This is the main conceptual difference from injecting growth hormone itself, which bypasses the system and suppresses the body’s own production.
Visceral fat (the fat packed around the abdominal organs) is more responsive to growth hormone’s fat-mobilizing effect than fat under the skin. That’s one reason tesamorelin reduces deep abdominal fat preferentially, and why people with low GH levels tend to accumulate it.
A Canadian drug: the Theratechnologies story
Tesamorelin is one of the few peptides discussed in the research community that was discovered and developed in Canada. Theratechnologies, based in Montreal, began work on stabilized GHRH analogues in the 1990s, and the lead clinical investigator on the pivotal trials, Dr. Julian Falutz, was based at the Montreal General Hospital. The program found its niche in HIV care.
In the late 1990s and 2000s, many people treated with early antiretroviral drugs developed HIV-associated lipodystrophy: fat loss in the face and limbs combined with fat build-up around the abdominal organs. This visceral fat was distressing and linked to metabolic risk. People with HIV also often had blunted growth hormone release. A drug that restored GH pulses to reduce visceral fat had a clear rationale.
After two phase 3 trials, the FDA approved Egrifta in November 2010. Theratechnologies regained the Canadian commercialization rights and Health Canada approved it on April 30, 2014. Later formulations (Egrifta SV, and a newer version, Egrifta WR) were developed to make the product easier to prepare and store.
The phase 3 visceral fat trials
Two randomized, double-blind, placebo-controlled phase 3 trials formed the basis for approval, with a combined total of over 800 participants.
| Trial | Participants | Duration | Change in visceral fat (tesamorelin) | Change in visceral fat (placebo) |
|---|---|---|---|---|
| Falutz 2007 (NEJM) | 412 | 26 weeks | −15.2% | +5.0% |
| Falutz 2010 (JAIDS) | 404 | 26 weeks | −10.9% | −0.6% |
| Pooled analysis (JCEM 2010) | 806 | 26 weeks | Treatment effect −15.4% vs placebo | |
Visceral fat was measured by CT scan, an objective measurement rather than a waist tape. Other results were consistent:
- Triglycerides fell (by 50 mg/dL vs a 9 mg/dL rise on placebo in the first trial) and the total-to-HDL cholesterol ratio improved.
- IGF-1 rose by about 81% in the first trial, as expected from increased GH release.
- Subcutaneous fat (under the skin) changed little, which was desirable for people who had already lost fat elsewhere.
- Body image scores, including belly appearance distress, improved compared with placebo.
- Body weight barely changed.
In the pooled analysis, people who stayed on tesamorelin for a full year maintained a visceral fat reduction of about 17.5% from baseline at week 52, along with lower waist circumference and triglycerides.
Who was in the trials
Knowing who was studied tells you how far the results can be stretched. The phase 3 participants were:
- Adults with HIV on stable antiretroviral therapy.
- Mostly men (86% in the first trial), which limits what can be said about women.
- People with excess abdominal fat defined by waist circumference and waist-to-hip ratio.
- Generally not people with poorly controlled diabetes, because of the glucose concern.
So the strongest evidence is for one specific group: people with HIV and treatment-associated central fat. Effects in people without HIV, in women, or in people with diabetes are much less well established, which is why the approval is so narrow.
Why visceral fat matters
Not all fat behaves the same way. Visceral fat is metabolically active: it releases fatty acids and inflammatory signals directly into the portal vein, which drains to the liver. Higher visceral fat is linked with insulin resistance, fatty liver, high triglycerides and cardiovascular disease, even in people whose overall weight is normal.
That is why a drug that reduces visceral fat without changing body weight can still matter. It also explains why tesamorelin has become a research tool well beyond HIV: it is one of the few compounds that selectively targets visceral fat in humans, with CT-measured trial data to show it.
What happens when it’s stopped
The trials included extension phases that answered an important question. Participants who were switched from tesamorelin to placebo after 26 weeks rapidly lost the visceral fat improvement, as the authors of the second phase 3 trial put it, drifting back toward baseline. Those who continued on tesamorelin maintained the reduction.
Like the GLP-1 drugs, tesamorelin manages the problem for as long as it’s used and doesn’t cure it. This is consistent with its mechanism: once the extra GHRH signal stops, GH pulses return to their previous, blunted levels.
Liver fat: the 2014 and 2019 trials
Because visceral fat and liver fat are closely linked, researchers at Massachusetts General Hospital tested whether tesamorelin also reduces fat in the liver.
- Stanley 2014 (JAMA): in 50 people with HIV and abdominal fat accumulation, six months of tesamorelin reduced visceral fat and liver fat compared with placebo. Fasting glucose rose slightly in the first two weeks, but the difference from placebo was not significant at six months.
- Stanley 2019 (Lancet HIV): in 61 people with HIV and non-alcoholic fatty liver disease, one year of tesamorelin reduced liver fat fraction by about 37% relative to baseline compared with placebo, and 35% of the tesamorelin group (vs 4% on placebo) ended the year with liver fat below the 5% threshold that defines fatty liver.
These trials made tesamorelin an important reference compound in research on fatty liver disease, now called MASLD. They also showed something useful mechanistically: restoring GH pulses affects liver fat independently of large changes in body weight. For context on the broader field, see Fatty liver treatment in Canada.
Cognition in older adults
Growth hormone and IGF-1 both decline with age, and both act on the brain. In a 2012 randomized trial published in Archives of Neurology, Baker and colleagues gave tesamorelin or placebo for 20 weeks to 152 adults aged 55 to 87, including people with mild cognitive impairment and healthy older adults.
The tesamorelin group showed improvements in executive function (planning, mental flexibility) compared with placebo, with a trend for verbal memory. The benefit was similar in people with mild cognitive impairment and in healthy older adults. IGF-1 roughly doubled but stayed within the normal range, and body fat fell by about 7%.
This was a single, modest-sized trial and hasn’t led to an approved use. But it’s one of the more credible human findings for any GH secretagogue outside of body composition, and it’s why tesamorelin appears in cognitive aging research.
Other research directions
| Area | What’s been studied | Status |
|---|---|---|
| Abdominal obesity without HIV | Small studies of visceral fat in people with obesity and relatively low GH | Early; not an approved use |
| HIV-associated cognitive changes | Trials building on the 2012 cognition findings | Investigational |
| Muscle and physical function | Secondary outcomes in fat trials | Small or inconsistent effects |
| Cardiovascular risk markers | Triglycerides, carotid wall thickness | Some favourable signals; no outcome trials |
Glucose and IGF-1: the two numbers to watch
Growth hormone has two well-known metabolic effects that make any GH-raising compound a trade-off.
Blood sugar
GH opposes insulin: it makes muscle and liver less responsive to it. In the pooled phase 3 analysis, there were no clinically meaningful differences in glucose measures between tesamorelin and placebo at 26 or 52 weeks. In the JAMA liver study, fasting glucose rose a little in the first two weeks and then settled. In the cognition trial, fasting insulin rose by about a third in people with mild cognitive impairment, though it stayed within the normal range. The overall picture is a small, mostly transient effect in people without diabetes. The label still carries a warning, and people with diabetes need closer monitoring.
IGF-1
IGF-1 is the main messenger for GH’s growth effects. Tesamorelin raises it substantially (by 81% in the first trial, and more than doubling it in older adults), though in the trials it generally stayed in the physiological range. That matters because persistently high IGF-1 is linked to tissue overgrowth and is a theoretical concern for cancer risk. It’s why active cancer is a contraindication, and why IGF-1 monitoring was part of approved use.
When comparing GH secretagogues in vitro or in animal models, measuring both a lipolysis endpoint and an insulin-signalling endpoint gives a more honest picture than lipolysis alone. The trade-off is the whole story with this class.
Side effects and safety
The Egrifta trials and prescribing information give a clearer picture of side effects than exists for most research peptides. The most frequently reported effects were:
- Injection-site reactions: redness, itching, pain.
- Joint pain (arthralgia), muscle pain and pain in the extremities, typical of raised growth hormone.
- Peripheral swelling (edema), from fluid retention.
- Numbness or tingling, including carpal tunnel-like symptoms.
Important warnings on the label include:
- Blood sugar: growth hormone counteracts insulin, so tesamorelin can raise glucose and increase the risk of developing diabetes. Glucose monitoring was part of approved use.
- IGF-1: levels rise and were monitored. Persistently high IGF-1 is a concern because of its growth-promoting effects.
- Active cancer: contraindicated, because GH and IGF-1 can stimulate cell growth.
- Pregnancy: contraindicated.
- Pituitary or hypothalamic disease, surgery or radiation: contraindicated.
- Hypersensitivity and antibodies: some patients developed antibodies, usually without clinical consequences.
A full breakdown is in Tesamorelin side effects (French version: Effets secondaires de la tésamoréline).
Tesamorelin vs CJC-1295 vs ipamorelin vs HGH
Tesamorelin is often grouped with other growth hormone secretagogues sold as research peptides. The differences are substantial.
| Tesamorelin | CJC-1295 | Ipamorelin | Growth hormone (somatropin) | |
|---|---|---|---|---|
| Mechanism | GHRH analogue | GHRH analogue (long-acting) | Ghrelin receptor agonist | Replaces GH directly |
| Preserves natural pulses? | Yes | Partly (DAC version raises baseline GH) | Yes | No |
| Approved drug? | Yes (Egrifta) | No | No | Yes (various) |
| Phase 3 data | Yes, over 800 people | No | No | Yes |
| Main human evidence | Visceral fat, liver fat, cognition | Hormone levels in healthy adults | Post-surgical gut trials (did not meet goals) | GH deficiency, growth disorders |
Detailed comparisons: CJC-1295 vs tesamorelin vs ipamorelin and CJC-1295 and ipamorelin.
Is tesamorelin a weight-loss drug?
No, and this is the most common misunderstanding about it. In the phase 3 trials, body weight barely changed. Tesamorelin redistributes fat: it reduces deep abdominal fat with little effect on total weight. Compared with the GLP-1 drugs, which produce 15% to 21% average weight loss, it’s a fundamentally different tool.
Where it’s interesting is precisely in that selectivity. Researchers interested in visceral fat as a driver of metabolic disease can use tesamorelin to reduce it without the confounding effect of large weight loss. Our overview of the field is in Peptides for weight loss.
Tesamorelin vs GLP-1 drugs for visceral fat
It’s a fair question now that semaglutide and tirzepatide are widely available. GLP-1 drugs also reduce visceral fat, substantially, but they do it as part of overall weight loss. Fat comes off everywhere, including from under the skin, and some lean mass goes with it.
| Tesamorelin | GLP-1 drugs (semaglutide, tirzepatide) | |
|---|---|---|
| Main mechanism | Restores GH pulses; GH mobilizes visceral fat | Reduces appetite and food intake |
| Total weight change | Minimal | 15–21% average in obesity trials |
| Visceral fat | About 15% reduction in 26 weeks | Large reductions, proportional to weight loss |
| Subcutaneous fat | Largely preserved | Reduced |
| Lean mass | Generally preserved | Some loss |
| Glucose | Can rise | Falls |
For someone with HIV-associated lipodystrophy, who may already have lost fat from the face and limbs, losing more subcutaneous fat is undesirable, and that is why tesamorelin’s selectivity was valuable. For people with obesity in general, the GLP-1 drugs produce far larger metabolic benefits. For researchers, the contrast is useful: the two classes let you separate the effects of visceral fat reduction from the effects of overall weight loss.
Legal status in Canada, the US and sport
- Canada: approved by Health Canada (2014) as Egrifta, a prescription drug, for HIV-associated abdominal fat. Use for any other purpose would be off-label and requires a prescriber. Research-grade tesamorelin is sold as a laboratory reagent, not for human use. Health Canada named tesamorelin among unauthorized injectable peptides seized from a Canadian seller in August 2025.
- United States: FDA-approved (2010) for the same indication.
- Sport: prohibited at all times by WADA as a growth hormone releasing factor (section S2).
Health Canada’s April 2026 advisory against injecting peptides bought online applies here too: research-grade material is not made to pharmaceutical standards and is not a substitute for a prescribed product.
Four common myths about tesamorelin
“It’s a safer HGH.”
It works differently from HGH and preserves natural feedback, but it is still a growth hormone-raising drug with the same class of effects: fluid retention, joint pain, raised IGF-1 and an effect on glucose. “Safer” has never been tested head-to-head.
“It burns belly fat in anyone.”
The phase 3 evidence is in people with HIV, most of them men, who had treatment-associated fat build-up and often blunted GH release. Whether the same magnitude of effect applies in other groups is not established.
“Results are permanent.”
Not in the trials. The visceral fat reduction was lost when people switched to placebo.
“It’s just another research peptide.”
Tesamorelin is unusual: it has been through the full drug development process, with two phase 3 trials and approvals in the US and Canada. That gives researchers a far better-characterized starting point than most compounds sold in the same category.
For researchers
Tesamorelin is a useful tool for several kinds of laboratory work:
- GHRH receptor pharmacology and signalling in pituitary cell models.
- Comparisons between GHRH analogues (tesamorelin vs CJC-1295) and ghrelin-receptor agonists (ipamorelin).
- Studies of DPP-4 resistance and peptide stability, given its specific modification.
- Adipocyte and hepatocyte models of GH-driven lipolysis and liver fat.
TrueLabs supplies tesamorelin in 2 mg vials from $37, with batch COAs in the COA library. As a 44-amino-acid peptide, identity confirmation by mass spectrometry is especially important; see How to read a peptide COA. For storage, see How to store peptides.
FAQ
Tap a question to reveal the answer.
What is tesamorelin used for?
Tesamorelin is approved, as Egrifta, to reduce excess abdominal (visceral) fat in adults living with HIV who have lipodystrophy. It has also been studied for liver fat and for cognition in older adults.
Is tesamorelin approved in Canada?
Yes. Health Canada approved Egrifta (tesamorelin) on April 30, 2014, for excess abdominal fat in adults with HIV-associated lipodystrophy. It is a prescription drug.
Who makes tesamorelin?
Tesamorelin was developed by Theratechnologies, a pharmaceutical company based in Montreal, Quebec.
Does tesamorelin cause weight loss?
Not significantly. In the phase 3 trials, it reduced visceral fat by about 15% over 26 weeks, but overall body weight barely changed.
How is tesamorelin different from HGH?
HGH replaces growth hormone directly and suppresses the body’s own production. Tesamorelin stimulates the pituitary to release more of its own growth hormone, preserving natural pulses and feedback.
What are the main side effects of tesamorelin?
Injection-site reactions, joint and muscle pain, swelling of the extremities and numbness or tingling. It can also raise blood sugar and IGF-1 levels, which were monitored in approved use.
Is tesamorelin better than CJC-1295?
They are both GHRH analogues, but tesamorelin has phase 3 trial data and regulatory approval, while CJC-1295 has only small hormone studies in healthy adults. They have not been compared head-to-head.
Does the visceral fat come back after stopping tesamorelin?
Yes. In trial extensions, people switched from tesamorelin to placebo quickly lost the visceral fat reduction, while those who continued kept it for up to 52 weeks.
Is tesamorelin banned in sport?
Yes. WADA prohibits growth hormone releasing factors, including tesamorelin, at all times under section S2 of the Prohibited List.
Can you buy tesamorelin in Canada?
As a medicine, tesamorelin (Egrifta) requires a prescription and is approved only for HIV-associated abdominal fat. Research-grade tesamorelin is sold in Canada as a laboratory reagent for in vitro research, not for human use. Health Canada has warned against injecting peptides bought online.
What is the difference between Egrifta, Egrifta SV and Egrifta WR?
They are formulations of the same drug. The later versions were designed to simplify preparation and storage for patients; the active ingredient, tesamorelin, is the same.
Related reading
- Tesamorelin side effects
- CJC-1295 vs tesamorelin vs ipamorelin
- Ipamorelin research guide
- Peptides for weight loss
- What is MOTS-c?
References
- Falutz J, Allas S, Blot K, et al. Metabolic effects of a growth hormone-releasing factor in patients with HIV. N Engl J Med. 2007;357:2359–2370. PubMed
- Falutz J, Potvin D, Mamputu JC, et al. Effects of tesamorelin, a growth hormone-releasing factor, in HIV-infected patients with abdominal fat accumulation: a randomized placebo-controlled trial with a safety extension. J Acquir Immune Defic Syndr. 2010;53:311–322. PubMed
- Falutz J, Mamputu JC, Potvin D, et al. Effects of tesamorelin (TH9507) in HIV-infected patients with excess abdominal fat: a pooled analysis of two multicenter, double-blind placebo-controlled phase 3 trials with safety extension data. J Clin Endocrinol Metab. 2010;95:4291–4304. PubMed
- 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;312:380–389. PubMed
- Stanley TL, Fourman LT, Feldpausch MN, et al. Effects of tesamorelin on non-alcoholic fatty liver disease in HIV: a randomised, double-blind, multicentre trial. Lancet HIV. 2019;6:e821–e830. PubMed
- Baker LD, Barsness SM, Borson S, et al. Effects of growth hormone-releasing hormone on cognitive function in adults with mild cognitive impairment and healthy older adults: results of a controlled trial. Arch Neurol. 2012;69:1420–1429. PubMed
- Ferdinandi ES, et al. Non-clinical pharmacology and safety evaluation of TH9507, a human growth hormone-releasing factor analogue. Basic Clin Pharmacol Toxicol. 2007;100:49–58. PubMed
- Theratechnologies. Health Canada approves EGRIFTA (tesamorelin for injection). April 30, 2014. GlobeNewswire
- EGRIFTA (tesamorelin for injection) prescribing information. FDA label
- Health Canada. Advisory RA-77807: Unauthorized injectable peptide drugs seized and sold by Canada Peptide. August 1, 2025. Recalls and Safety Alerts
This article summarizes published research and regulatory information for information only and is not medical advice. TrueLabs research compounds are sold for in vitro and laboratory research use only and are not intended for human or veterinary use.