Tesamorelin Is Approved, for One Thing, at a Dose Nobody Quotes

What it is

Your brain makes a peptide called growth hormone releasing hormone. It binds to a small gland at the base of your skull and makes it put out a burst of growth hormone. Tesamorelin is a synthetic copy of that signal, modified to last longer in the blood after an injection. The United States regulator approved it in November 2010 as Egrifta, for the excess deep abdominal fat that builds up in some adults with HIV, the virus that causes AIDS. Its label says under Limitations of Use that it "is not indicated for weight loss management as it has a weight neutral effect."

What the trials show

The two the approval was based on, both run by the manufacturer, Theratechnologies.

Falutz and colleagues published the first in the New England Journal of Medicine in 2007. They divided 412 HIV positive adults with excess abdominal fat at random between 2 mg of tesamorelin injected under the skin daily and a placebo, an inactive injection given the same way, for 26 weeks. Neither the participants nor the clinicians knew who was on which. Deep abdominal fat, measured as an area on a cross sectional scan, fell 15.2 percent on the drug and rose 5.0 percent on the dummy. Insulin like growth factor 1, a growth signal the liver puts out when growth hormone reaches it, rose 81.0 percent on the drug and fell 5.0 percent on the dummy. Both differences carried a P value below 0.001, meaning a gap that size would turn up by chance less than once in a thousand runs if the drug did nothing. (PMID 18057338)

A second trial repeated the design in 404 patients at the same dose and found a smaller but still real drop, 10.9 percent against 0.6 percent on placebo, about 21 cm² off the scan. (PMID 20101189)

Pooled, 806 adults, all on the drug combination that keeps HIV suppressed, 543 on tesamorelin and 263 on placebo. Deep abdominal fat fell an average of 24 cm² and rose 2 cm² on placebo. The fat directly under the skin, the stuff you can pinch, was essentially unchanged, at a P value of 0.08, too small to separate from chance. (PMID 20554713)

There are two fat compartments in an abdomen and this drug works on the one behind the muscle wall, around the organs. Imagine a house with a filled loft and a filled hallway. It empties the loft, and every room you walk through looks the same.

Among the 246 who stayed on it to week 52, deep abdominal fat was down 35 cm², or 17.5 percent. That is where the 18 percent visceral fat figure in vendor copy comes from.

Off the drug it comes back. In the extension phase of the second trial, the group switched from drug to placebo put 24 cm² back on while the group kept on it lost a further 11. (PMID 20101189) Outside the indication it gets run in cycles, weeks on and weeks off. Every trial dosed continuously, and I found no published evaluation of cycling.

Liver fat, in HIV. Stanley and colleagues in Lancet HIV 2019 gave 2 mg daily for a year to 61 people with HIV whose livers were at least 5 percent fat on a scan. Liver fat fell 4.1 percentage points further than placebo, a 37 percent relative drop, P value 0.018. (PMID 31611038)

One of the trials you might find is fake. Search the United States government's trial registry for tesamorelin and liver fat and the first result, NCT07481734, is a forgery that uses the word mock twice, once in its title and once in its description. On 31 July 2026 Morgan McSweeney published an investigation into eight registrations under a sponsor called Hudson Biotech, all at one hospital in Shenzhen, all recruiting, covering the grey market peptide catalogue almost exactly. (Dr Noc) I ran the same query and got the same eight. Only the peptide records say mock, and two others copy real Eli Lilly obesity trials while admitting nothing, so the sponsor name is the tell rather than the title. A genuine peptide company shares part of that name, and McSweeney was careful to note no connection has been shown.

Outside HIV the evidence thins out fast. Makimura and colleagues gave 2 mg daily for a year to 60 adults with abdominal obesity and reduced growth hormone output, and deep abdominal fat came out 35 cm² lower than placebo, P = 0.003, with no significant change in blood sugar. (PMID 23015655) Sixty people, chosen for low growth hormone.

The cognitive claim rests on one study. Baker and colleagues gave 1 mg under the skin half an hour before bed to 152 adults aged 55 to 87, 66 of them with mild cognitive impairment, for 20 weeks, and found an improvement in executive function, the mental machinery for planning and switching tasks. (PMID 22869065) A test score at 20 weeks, not a study of who later developed dementia. It is also where the advice to inject before bed comes from.

The safety figures that do not make it into the sales copy. At 26 weeks, 47 percent of patients were more than 2 standard deviations above the average insulin like growth factor 1 for their age and sex, and 36 percent were more than 3. A standard deviation score counts how far a result sits from the average, and above 2 is outside where nearly everyone healthy falls. The label tells physicians to monitor that hormone and stop the drug if it stays above 3, which nobody buying research use only vials can do. New high blood sugar, an HbA1c of 6.5 percent or higher on a test reflecting average blood sugar over about three months, showed up at week 26 in 5 percent of the treated group against 1 percent on placebo. The trial abstracts report no change in blood sugar and the label reports this difference. Only the first travels.

Where the 2 mg came from

The approved dose everyone quotes is 2 mg daily, approved in 2010. The National Library of Medicine's LiverTox entry says the same. That product is gone.

What is sold now is Egrifta SV at 1.4 mg once daily, and Egrifta WR, approved in March 2025 to replace it, at 1.28 mg. Both labels say the formulations are not substitutable, which means you cannot swap one for the other at the same number: different powder strengths, a different number of vials per dose, different mixing steps, different storage. Someone measuring out of a grey market vial to hit "the approved 2 mg" is aiming at a product that no longer exists.

Why people do it anyway. A Canadian review recorded a submitted price of $3,085 for a box of 60 vials, a 30 day supply, against grey market listings around $150 for a 10 mg vial.

Sermorelin, CJC-1295 and modified GRF 1 to 29 are shorter analogues of the same signal. None has evidence like the above, and Egrifta's approval gets invoked for all of them.

What no one seems to know

Whether it changes how you look. The compartment it empties is the one a mirror cannot show you, and in 806 people the visible layer did not move.

What it does long term. The ten year cohort meant to establish tumour and cardiovascular safety, NCT01579695, enrolled 391 people, ran from February 2013 to August 2018, and stopped with the reason field blank. The longest anyone stayed on the drug inside the approval programme was 52 weeks.

Whether cycling helps. Untested, and the extension data point the other way.

Whether any of it carries to people without HIV. Two randomised studies in selected populations, and nothing I could find in healthy trained adults for muscle or performance across the registry's 24 tesamorelin records.

My opinion

Approval is a permission slip for one thing, and I think it makes tesamorelin more misleading than the compounds here with no approval at all, because it hands a seller a real document to wave. Anyone buying it for how they look is paying to empty a compartment no mirror can show them. The fake registry record bothers me more than the marketing does, because an identifier starting with NCT reads as a citation to almost everybody, and this one shouts its own fiction in the title and still comes up first.

If you have seen tesamorelin for sale, I want to know whether the vendor used the phrase weight neutral anywhere, and which dose figure they quoted if they did.

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This content is for educational and informational purposes only and is not medical advice. Peptides discussed are research compounds and may not be approved for human use. Nothing here should be used to diagnose, treat, cure, or prevent any disease. Always consult a qualified healthcare professional before starting any peptide, supplement, or protocol. Individual responses vary. Do not self-administer compounds without proper medical supervision.