Tesamorelin

Tesamorelin in brief

Three numbers frame the drug: what it did to visceral fat against placebo, what it did to IGF-1, and how long a single injection actually lasts.

Every figure on this page is taken from a PubMed abstract or from the EGRIFTA prescribing information, all listed at the end. Tesamorelin doses are quoted only where the label or a trial abstract states them; how gym users describe the tesamorelin peptide is reported as their description, not as a protocol.

What this tesamorelin guide covers

What is tesamorelin? A stabilised GHRH with a label

Growth hormone releasing hormone, GHRH, is a 44-amino-acid peptide from the hypothalamus that binds receptors on the pituitary somatotrophs and drives the synthesis and pulsatile release of growth hormone. Tesamorelin is that full sequence with a trans-3-hexenoic acid group on the N-terminus that protects it from the enzyme dipeptidyl peptidase IV, which otherwise inactivates GHRH within minutes. The label describes it as binding and stimulating human growth hormone releasing factor receptors with a potency similar to the endogenous hormone, and stimulating the synthesis and pulsatile release of endogenous growth hormone (EGRIFTA prescribing information).

The design goal was different from CJC-1295. Where CJC-1295 was engineered to bind albumin and stay in the blood for a week, tesamorelin keeps the natural short life of the hormone, an elimination half-life of 11 minutes with a median time to peak of 0.15 hours and subcutaneous bioavailability below 4 percent, and relies on a daily injection to deliver one physiological pulse a day (EGRIFTA prescribing information). Two weeks of that pulse in 13 healthy men raised mean overnight growth hormone, pulse area and basal secretion, and raised IGF-1 by 181 micrograms per litre, while insulin-stimulated glucose uptake on a euglycemic clamp was preserved (PMID 20943777).

The three formulations matter because the trials, the forum posts and the vendor listings quote different milligram figures for what is meant to be the same daily exposure. The 2 mg dose is the one in every trial abstract on this page; the 1.4 mg and 1.28 mg doses are newer formulations of the same drug with higher bioavailability per milligram, designed to give the same effect with less powder (EGRIFTA prescribing information). A vial of research-grade tesamorelin bought online is labelled in milligrams of peptide and says nothing about which formulation it resembles. The naming of these compounds is on types of peptides.

The EGRIFTA label: dose, contraindications, warnings

Tesamorelin is the one peptide on this site where the dose question has an official answer, so the label is quoted in full rather than paraphrased. The indication is the reduction of excess abdominal fat in HIV-infected adult patients with lipodystrophy. The recommended dose is 2 mg subcutaneously once daily for the original EGRIFTA, 1.4 mg once daily for EGRIFTA SV, and 1.28 mg once daily into the abdomen for EGRIFTA WR, where one 11.6 mg vial reconstituted with 1.3 ml of bacteriostatic water provides seven daily doses of 0.16 ml (EGRIFTA prescribing information).

Two sentences on the label matter more than the rest for anyone who arrived here from a fat-loss search. The first: EGRIFTA is not indicated for weight loss management and has a weight-neutral effect (EGRIFTA prescribing information). The trials moved visceral fat on a CT scan, not the scale. The second: the long-term cardiovascular safety of the drug has not been established (EGRIFTA prescribing information), which is the caveat on every number in the next section.

The tesamorelin trials: what was measured in HIV lipodystrophy

The programme began with a dose-ranging study. Sixty-one HIV patients with increased waist circumference were randomised to placebo, 1 mg or 2 mg of the compound then called TH9507 once daily for 12 weeks; IGF-1 rose 48 percent on 1 mg and 65 percent on 2 mg, trunk fat fell 9.2 percent on 2 mg against a 0.8 percent rise on placebo, visceral fat fell 15.7 percent on 2 mg but not significantly against placebo in that small sample, subcutaneous fat was preserved, triglycerides and the cholesterol to HDL ratio improved, and glucose did not change (PMID 16052083). The 2 mg dose went forward to phase 3 (PMID 18057338).

The first phase 3 trial is the one on the label. Four hundred and twelve patients, 86 percent men, received 2 mg of tesamorelin or placebo daily for 26 weeks (PMID 18057338). Visceral fat on CT fell 15.2 percent against a 5.0 percent rise; triglycerides fell 50 mg per decilitre against a 9 mg rise; the total to HDL cholesterol ratio fell 0.31 against a 0.21 rise, all with p below 0.001; IGF-1 rose 81.0 percent against a 5.0 percent fall; adverse events did not differ but more patients on tesamorelin withdrew because of one; glycemic measures did not differ (PMID 18057338).

The extension answered the question every fat-loss reader asks. At week 26 the tesamorelin patients were re-randomised to continue or switch to placebo. Those who continued held a visceral fat reduction of 18 percent over 52 weeks and a triglyceride fall of 51 mg per decilitre, glucose changes were not clinically significant, adverse events in the extension matched the first phase, and in the patients who switched to placebo the visceral fat reaccumulated (PMID 18690162). The abstract closes with the sentence that defines the drug: the effects do not last beyond the duration of treatment.

The second phase 3 trial repeated the design in 404 patients. Visceral fat fell 10.9 percent, 21 square centimetres, against 0.6 percent on placebo at six months; trunk fat, waist circumference and waist to hip ratio improved with no change in limb or abdominal subcutaneous fat; patient distress about belly appearance improved; IGF-1 rose; glucose did not change; visceral fat was down about 18 percent in patients who continued for 12 months, and the gains were rapidly lost in those switched to placebo (PMID 20101189).

Liver fat became the second target. In a six-month trial of 50 patients, tesamorelin reduced visceral fat by 34 square centimetres against an 8 square centimetre rise, and cut the liver lipid to water fraction by 2.0 percent against a 0.9 percent rise; fasting glucose rose 7 mg per decilitre more than placebo at two weeks but the difference had gone by six months (PMID 25038357).

The 12-month multicentre trial in 61 people with HIV and fatty liver disease found a 37 percent relative reduction in hepatic fat fraction and no difference in glucose or HbA1c, with more injection-site complaints on drug (PMID 31611038). In the 38 participants of that trial who were on integrase inhibitors, the antiretrovirals now associated with weight gain, visceral fat fell 25 square centimetres against a 14 square centimetre rise and liver fat fell 4.2 percent against 0.5 percent, with a similar frequency of hyperglycemia in both groups (PMID 38905488).

A 2026 meta-analysis of five randomised trials pooled the results: visceral fat down 27.71 square centimetres, trunk fat down 1.18 kg, limb fat down 0.22 kg, hepatic fat down 4.28 percentage points, waist down 1.61 cm, lean mass up 1.42 kg, no significant change in subcutaneous fat or BMI, and adverse events of arthralgia, myalgia, paresthesia and injection-site erythema without serious events or glucose perturbation (PMID 41545261). A CT density analysis of 341 participants from the two phase 3 trials added that fat quality improved as well as quantity: visceral and subcutaneous fat density rose by 6.2 and 4.0 Hounsfield units on tesamorelin against 0.3 on placebo, independent of the area lost (PMID 33756511).

Tesamorelin without HIV: obesity, diabetes, healthy men and the ageing brain

The label stops at HIV, but the trials did not, and the studies in people without HIV are the ones most relevant to anyone reading this for their own waistline. The closest match is a 12-month randomised trial of 60 abdominally obese adults with reduced growth hormone secretion, chosen because obesity suppresses the axis. On 2 mg daily, visceral fat fell 16 square centimetres against a 19 square centimetre rise on placebo, carotid intima-media thickness fell 0.04 mm more than placebo, C-reactive protein and triglycerides improved, subcutaneous fat did not change, IGF-1 rose 86 micrograms per litre, fasting and two-hour glucose and HbA1c did not change, and there were no serious adverse events (PMID 23015655).

A substudy of 39 of those subjects linked the IGF-1 rise to faster phosphocreatine recovery in muscle after exercise, a marker of mitochondrial function (PMID 24178787).

The diabetes question was tested directly. Fifty-three patients with type 2 diabetes received placebo, 1 mg or 2 mg for 12 weeks: the insulin response to oral glucose, fasting glucose, HbA1c and overall diabetes control did not differ between groups, no patient left for loss of glycemic control, and total and non-HDL cholesterol fell on 2 mg (PMID 28617838). In healthy men, two weeks of 2 mg daily raised IGF-1 by 181 micrograms per litre with no change in fasting glucose or clamp-measured insulin sensitivity (PMID 20943777).

The cognition trial is the one that travels furthest from the label and the one most often quoted out of context. One hundred and fifty-two adults aged 55 to 87, including 66 with mild cognitive impairment, self-injected 1 mg of tesamorelin or placebo 30 minutes before bed for 20 weeks; cognition improved on the composite score with p equal to 0.03, executive function with p equal to 0.005, IGF-1 rose 117 percent while staying in the physiological range, body fat fell 7.4 percent, and fasting insulin rose 35 percent within the normal range in the impaired group (PMID 22869065).

A later open-label trial in people with HIV found no clear cognitive benefit (PMID 39813152). Note the population in the positive trial: older adults whose growth hormone axis has declined with age, not young men whose axis is intact.

The tesamorelin peptide in the gym: how users describe it, and what is measured

This is the section the label cannot write, so the page reports two things separately: how users and the vendors who sell to them describe the tesamorelin peptide in practice, and the measured data that any of it could rest on. Nothing in the first half is evidence. It is a description of a pattern, and a pattern people describe is not a dose anyone should copy.

What users describe. On bodybuilding forums the tesamorelin peptide is sold as research-grade lyophilised powder in 5 mg or 10 mg vials, reconstituted with bacteriostatic water and drawn on an insulin syringe (forum posts). The dose users most often describe is 2 mg once a day, some going to 2.5 mg, with a minority describing 1 mg nightly on the grounds that the cognition trial used it; the timing they describe is a single injection as close to falling asleep as possible, at least an hour after the last meal, because they believe insulin blunts the growth hormone pulse (forum posts).

Runs are described as continuous for months rather than in cycles, on the argument that the HIV trials ran for a year without loss of effect, and the usual recommendation in the threads is to commit to six months before judging results (forum posts).

The stacks users describe are ipamorelin at 100 to 600 micrograms alongside, or CJC-1295 with GHRP-2, and the compound is usually described as running on top of testosterone replacement (forum posts). The reasons given are visceral fat, sleep and recomposition. The dissent in the same threads is about cost, since a month at the described dose consumes several vials, and about non-response: one user who ran 2.5 mg daily for over a month reported no result and an IGF-1 that had not risen (forum posts).

What the reasons rest on. The visceral fat idea is the best supported claim on this site: five randomised trials in HIV lipodystrophy, one in obese adults without HIV, and a meta-analysis all point the same way (PMID 41545261, PMID 23015655). Two qualifications travel with it. The effect is on visceral fat measured by CT, with subcutaneous fat unchanged and body weight neutral according to the label, which is not what a mirror or a scale shows (EGRIFTA prescribing information); and the fat returned within months of stopping in the extension study (PMID 18690162).

The sleep idea rests on growth hormone physiology and on the overnight secretion data in healthy men (PMID 20943777), which measured hormones, not sleep. The recomposition idea has one number behind it, 1.42 kg of lean mass in the meta-analysis of HIV patients (PMID 41545261).

What is measured that a lifter could use. First, IGF-1: it rose 81 percent in the pivotal trial and the label asks for it to be monitored, with discontinuation considered above 3 SDS (PMID 18057338, EGRIFTA prescribing information); anyone running the peptide who then has bloodwork drawn should expect that number to be high, and the blood tests before steroids page explains what it normally means.

Second, glucose: the label records new glucose intolerance in 5 percent against 1 percent with a hazard ratio of 3.3 (EGRIFTA prescribing information), even though the trials in diabetes and healthy men found no change (PMID 28617838, PMID 20943777).

The honest summary for a lifter is that tesamorelin is the one growth hormone secretagogue with real fat data, that the data are in people whose axis was suppressed, and that the label itself says it is not a weight-loss drug. How to read a research-chemical listing against a trial is on peptide research vs human use.

Tesamorelin side effects by the evidence

Tesamorelin side effects are unusually well documented for a peptide on this site, because the label carries an adverse reaction table against placebo and the trials ran for a year. The pattern is the pattern of growth hormone excess, mild in most patients, plus injection-site reactions and a hypersensitivity rate that is not trivial.

The honest summary of tesamorelin side effects is that they are the side effects of more growth hormone, that they were mostly mild over a year in the trials, that the label has enough placebo-controlled numbers to say so, and that the three things it cannot say are what happens after a year, what happens in a person whose axis was never low, and what happens to the heart, because the label states that cardiovascular safety has not been established. The general page on peptide side effects covers the injection-site and sterility problems shared by every reconstituted peptide.

Tesamorelin vs sermorelin, CJC-1295 and ipamorelin

Four names share the search results. Three act at the same GHRH receptor and one at the ghrelin receptor; only one has a label. The differences are evidence and duration, not mechanism.

Tesamorelin vs sermorelin. Sermorelin is the first 29 amino acids of the hormone tesamorelin copies in full. Both act at the same receptor and both clear in minutes; the difference is that tesamorelin finished a phase 3 programme and sermorelin's human data are limited to growth hormone and IGF-1 responses in children and the elderly (PMID 8329826, PMID 9360512). Search interest in sermorelin vs tesamorelin is large; the head-to-head trial does not exist.

Tesamorelin vs CJC-1295. Tesamorelin is what CJC-1295 was meant to become. Both were developed for the visceral fat of HIV lipodystrophy; tesamorelin was approved and CJC-1295 stopped after phase 1 (PMID 16352683). The full record of the other compound is on CJC-1295. The tesamorelin ipamorelin blend sold online combines an approved drug with a ghrelin mimetic whose only human efficacy trial was negative (PMID 25331030), and the combination has never been tested; the other half of that blend is on ipamorelin.

Five mistakes people make about tesamorelin

Each comes from reading the label as a fat-loss licence, or a trial in one population as a promise for another.

1. Calling it an approved fat-loss drug. The label says EGRIFTA is not indicated for weight loss management and has a weight-neutral effect (EGRIFTA prescribing information). It reduces visceral fat on a CT scan in HIV lipodystrophy; the scale did not move.

2. Expecting the result to stay. Visceral fat reaccumulated after stopping and the effects do not last beyond treatment (PMID 18690162, PMID 20101189). The forum consensus that it must be run for months is, for once, the same as the trial design.

3. Applying the numbers to a normal growth hormone axis. Every fat trial enrolled people with suppressed secretion, from HIV therapy, obesity or age (PMID 18057338, PMID 23015655, PMID 22869065). No trial has measured a young lifter with an intact axis.

4. Skipping the IGF-1 test. 47 percent of treated patients were above 2 SDS and 36 percent above 3 at 26 weeks, and the label tells prescribers to monitor and consider stopping (EGRIFTA prescribing information). A research vial comes with no such instruction.

5. Assuming the milligrams on a vial mean the label dose. The label dose is 2 mg, 1.4 mg or 1.28 mg depending on formulation because bioavailability differs between them (EGRIFTA prescribing information). A research-grade powder resembles none of them in any tested way.

Verdict: the one growth hormone peptide with real fat data, for a specific patient

Tesamorelin, after the label and the abstracts rather than the vendor pages, is the best-evidenced peptide in its class by a wide margin: five randomised trials in HIV lipodystrophy, a 12-month trial in obese adults without HIV, a diabetes safety trial, a cognition trial in older adults, a 2026 meta-analysis, and a label with placebo-controlled adverse reaction rates. Visceral fat fell 15 to 18 percent and liver fat 37 percent while glucose held, and the fat came back when the injections stopped (PMID 18057338, PMID 31611038, PMID 18690162).

For readers here the practical conclusion is that the tesamorelin peptide is a real drug whose numbers belong to real patients, that its side effects are quantified and mostly mild but include a hypersensitivity rate of 4 percent and a glucose warning, and that the IGF-1 monitoring on its label is the difference between a prescription and a vial. The class is on growth hormone peptides, the compound it is most often compared with is on CJC-1295, and the arithmetic for any vial is on the peptide calculator.