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Peptides Explained

Growth-hormone axis

Tesamorelin

A US medicine for belly fat in HIV. Not approved in the EU; not shown to slow ageing.

Authorised outside the EU

At a glance

Is it an approved medicine?
Not in the EU Approved only in some countries outside the EU.
Has it been tested in people?
Yes Large trials in many people, checked by regulators.
Is it allowed in sport?
No Banned in sport at all times. Anti-doping list (WADA), section S2
What is the biggest risk?
Can raise blood sugar and IGF-1, a growth signal; long-term effects unknown. More about the risks

Status checked on . The details and sources are further down this page.

Stop and get help if you notice

  • Hives, swollen face or throat, hard to breathe2,79
  • Hot, red, swollen injection spot, or fever8,77
  • Worse eyesight, if you have diabetes2

If it is severe, call your local emergency number.

All warning signs, further down this page Warning signs for any peptide

The 30-second version

About 8 minutes for the short version; 36 with every detail open.

  • Tesamorelin is a lab-made version of a brain hormone. It makes the body release more growth hormone.
  • In the US it is a prescription medicine, Egrifta. It treats extra belly fat in adults with HIV.
  • It is not approved in the EU or the UK. The EU application was withdrawn in 2012.
  • In trials, deep belly fat shrank by about 15%. It grew back after people stopped.
  • It can raise blood sugar and IGF-1, a growth signal. Nobody knows what years of use do.
Class
Growth-hormone axis
How it is taken
Injection under the skin of the belly
How often
Once a day
Time in the blood
Half-life about 8 to 11 minutes
Approved for
Extra belly fat in adults with HIV, in the US
Status in the EU
Withdrawn
Tested in people
Yes

Label facts, not dosing advice. Sources are in the sections below.

Last reviewed
Fat tissue under a microscope: large, pale, many-sided fat cells with thin pink walls, packed tightly together.
Fat cells under a microscope. In trials, tesamorelin shrank deep belly fat, but only while it was used. Photo: Berkshire Community College Bioscience Image Library, Berkshire Community College Bioscience Image Library (Wikimedia Commons) CC0 1.0 Image details

Each section starts with the short answer. The rest is folded under “In detail”.

Evidence profile

Four separate questions. Not a score.

Human clinical evidence How far has it been tested in people?
Authorised by a regulator
Preclinical volume How much laboratory and animal research exists?
Minimal
Source independence How many independent groups produced it?
A few groups
Safety characterisation How well do we know the harms in humans?
Partial
In detail Why these grades: the reason for each step
Human clinical evidence
Authorised in the US since 10 November 2010 (Egrifta), on the basis of two randomised, double-blind phase 3 trials in 816 adults with HIV and extra belly fat, each with a 26-week extension. Not authorised in the EU: the application was withdrawn in 2012.
Preclinical volume
Minimal. A PubMed search on 22 October 2026 found 128 records on tesamorelin or TH9507, but only a handful of primary animal or laboratory studies: the developer's non-clinical paper (rats, dogs, pigs), a dog absorption study, two rat studies from Kenya and anti-doping laboratory methods. Most of the regulatory toxicology is known only from the US label.
Source independence
Few groups. The phase 3 trials were run and paid for by the developer, Theratechnologies. Most later trials come from one academic group at Massachusetts General Hospital: NIH-funded, but its senior author was senior author of the phase 3 reports and has been a consultant to the developer, which supplied the drug for its trials and part of the funding for one. Smaller trials come from the universities of Washington, California San Diego and Texas.
Safety characterisation
Partial. About 740 people were treated in the trials, for up to 52 weeks, and the medicine has been on the US market since 2010. But the FDA-required 10-year safety study and 3-year eye trial were stopped in 2018 with no results posted, and the label states that long-term heart safety and the effects of long-term high IGF-1 are not known.

We never add these up. A compound can have a large animal literature from one laboratory and no human data at all — that is a specific situation, and a single number would hide it. How we grade evidence

In detail The molecule: amino-acid sequence and technical details
Amino-acid sequence44 amino acids

(trans-3-hexenoyl)-Tyr-Ala-Asp-Ala-Ile-Phe-Thr-Asn-Ser-Tyr-Arg-Lys-Val-Leu-Gly-Gln-Leu-Ser-Ala-Arg-Lys-Leu-Leu-Gln-Asp-Ile-Met-Ser-Arg-Gln-Gln-Gly-Glu-Ser-Asn-Gln-Glu-Arg-Gly-Ala-Arg-Ala-Arg-Leu-NH2

Read from the N-terminus (start) to the C-terminus (end).

Modifications
position 1: Tyr1 carries a trans-3-hexenoyl group (a six-carbon chain with one double bond); it slows breakdown by the enzyme DPP-4. The 44 amino acids are otherwise those of human GHRH
Full name
N-(trans-3-hexenoyl)-human growth hormone-releasing hormone (1-44) amide
International non-proprietary name
tesamorelin
Also called
TH9507, TH-9507, (3E)-hex-3-enoylsomatoliberin
Authorised products
Egrifta, Egrifta SV, Egrifta WR
Class
Growth-hormone axis
Body systems
Hormones, Metabolism
Formula
C221H366N72O67S
Molecular mass
5,135.9 Da

What it actually is

What is tesamorelin?

A lab-made version of a brain hormone. In the US it is a prescription medicine called Egrifta.
Egrifta from a pharmacy and an online vial with the same name are not the same thing. What is known about each, from regulators' documents, checked on 22 October 2026.
Egrifta (US prescription medicine)A vial sold as “tesamorelin” outside the legal supply chain
Checked by a regulator?Yes Approved by the FDA since 2010; its label is kept up to date1,2No In 2026 the FDA warned online sellers that such products are unapproved new drugs3
Approved in the EU or the UK?No The EU application was withdrawn in 2012; the UK database lists no product4,5No No regulator has assessed it3
Contents and sterility known?Yes A sterile powder of known content, made by the licence holder2Unknown Not checked by any regulator3
Official risk information?Yes A label and leaflet with warnings2No None
Legal to supply in the Netherlands?No Not normally; only through a narrow named-patient route6No Supplying a medicine without a marketing authorisation is forbidden7

Tesamorelin is a medicine with real trials behind it, for one narrow use: deep belly fat in adults with HIV. It is on this site because vials sold online carry the same name.2,3 The authorised medicine itself is also a powder in a vial that is mixed before injection, so looking like Egrifta proves nothing.2

In detail The authorised products, and why this page looks different

The FDA approved Egrifta on 10 November 2010 to reduce excess abdominal fat in adults with HIV and lipodystrophy, a change in body fat seen in some people on HIV treatment.1,8 The 2 mg vial was renamed Egrifta SV on 5 July 2019, and a newer formulation, Egrifta WR, was approved on 25 March 2025.9,10 The licence holder is Theratechnologies.11

The label limits the approved use in three ways. Long-term heart safety has not been established; it is not for weight loss, because it does not change body weight; and there are no data that it helps people take their HIV medicines.2

In detail The molecule, and where the hormone was found

In 1982 a team led by Roger Guillemin isolated a 44-amino-acid peptide from a pancreatic tumour that had caused acromegaly, a disease of too much growth hormone. It turned out to be the hormone the brain uses to order growth-hormone release: growth hormone-releasing hormone, or GHRH.12

Tesamorelin is that same chain of 44 amino acids, Tyr-Ala-Asp-Ala-Ile-Phe-…-Arg-Ala-Arg-Leu-NH2, with one change: a hexenoyl group, a chain of six carbon atoms with one double bond, attached to the first amino acid, tyrosine.2,12,13 Its formula is C221H366N72O67S and its mass 5135.9 Da; the medicine contains it as an acetate salt.2,14

Why the extra group, and what it does not change

Natural GHRH can be cut at its start by the enzyme DPP-4, which inactivates it. In the developer’s laboratory tests, the hexenoyl group protected tesamorelin from DPP-4 and slowed its breakdown in rat, dog and human plasma.15 It is still short-lived: after an injection under the skin its half-life in healthy people is about 8 to 11 minutes, and less than 4% of the injected amount reaches the blood.2,11 It works as a short daily push on the body’s own system.

A peptide that US law counts as a protein

US law defines a protein as a chain of more than 40 amino acids.16 With 44, tesamorelin crossed that line, so on 23 March 2020 its approval was “deemed to be” a biologics licence.1 That matters for compounding (see the regulatory section).

How it works

What does it do in the body?

It makes the pituitary gland release more growth hormone. Deep belly fat then slowly shrinks.
How tesamorelin works, step by step, and how well each step is shown.
StepWhat happensWhere it was shown
1. The signalTesamorelin fits the GHRH receptor on growth-hormone cells in the pituitary gland, at the base of the brainCells in the lab
2. Growth hormoneThe pituitary releases more growth hormone, still in bursts13 healthy men
3. IGF-1The liver makes more IGF-1, a growth signalPhase 3 trials
4. Fat breakdownGrowth hormone makes fat cells release stored fat; blood sugar can riseHuman growth-hormone studies
5. Deep belly fatFat around the organs shrinks; fat under the skin hardly changesPhase 3 trials
6. The brakeGrowth hormone and IGF-1 slow the next burst (feedback)Human physiology
7. HealthFewer heart attacks, longer life, slower ageingNot tested

Sources 2, 17, 18, 19, 20, 4

Tesamorelin is not known to act on fat directly. It turns up the body’s own growth-hormone system. That is why its wanted and unwanted effects look like a milder version of growth hormone’s: less deep belly fat, but also fluid retention and higher blood sugar.21

In detail Step by step: the chain of effects and its evidence
The proposed causal chain, step by step

Each step is labelled with how well the link from the previous step is established.

  1. Step 1 Binding In cells

    A copy of the brain's growth-hormone signal

    Tesamorelin is human GHRH (1–44) with a hexenoyl group added to its first amino acid. In laboratory tests it binds and switches on the human GHRH receptor about as strongly as the natural hormone. The added group slowed breakdown by the enzyme DPP-4 in plasma samples; in people it still leaves the blood within minutes (half-life about 8–11 minutes).

  2. Step 2 Signal inside the cell In humans

    The pituitary releases more growth hormone, still in bursts

    GHRH acts on the growth-hormone cells of the front (anterior) pituitary gland. In 13 healthy men, two weeks of daily tesamorelin raised overnight growth hormone, both the bursts and the level between them. In the trials, other pituitary hormones did not change in a clinically significant way.

  3. Step 3 Cell response In humans

    The liver makes more IGF-1

    Growth hormone makes the liver and other tissues produce IGF-1. In the first phase 3 trial IGF-1 rose by 81% in 26 weeks; across the trials, more than a third of people (36%) had IGF-1 far above the normal range (more than 3 standard deviation scores) at 26 weeks.

  4. Step 4 Cell response In humans

    Fat cells release stored fat

    In people, growth hormone's most prominent metabolic effect is to increase the breakdown of stored fat (lipolysis). The fatty acids released also make the body respond less to insulin, which is why blood sugar can rise. This is growth-hormone physiology in humans, not measured for tesamorelin itself.

  5. Step 5 Tissue response In humans

    Deep belly fat shrinks; fat under the skin hardly changes

    On CT scans, fat around the organs (visceral fat) fell by about 15% more than with placebo in 26 weeks, while belly fat under the skin and body weight barely changed. Liver fat also fell in two smaller trials. Why visceral fat responds more is not established.

  6. Step 6 Effect on the body In humans

    The effect lasts only while it is used

    When people were switched to placebo after 26 weeks, their deep belly fat grew back by 16–22% within the next 26 weeks.

  7. Step 7 Effect on the body Hypothesised

    Better health or slower ageing: not shown

    No published trial has measured heart attacks, strokes, liver failure or deaths as its main result. The EU regulator's committee judged that the fat reduction had not been shown to bring real health benefits.

What each step rests on

The receptor. The US label states that, in laboratory tests, tesamorelin binds and stimulates human GHRH receptors with a potency similar to the body’s own hormone.2 GHRH is made in the hypothalamus and acts on the growth-hormone cells (somatotrophs) of the pituitary.2,20

Growth hormone in bursts. Growth hormone is normally released in pulses, driven by GHRH and held back by somatostatin.20 In 13 healthy men given tesamorelin daily for two weeks, without a comparison group, overnight growth hormone rose, both in its peaks and between them, and IGF-1 rose by 181 µg/L .17 In the trials, other pituitary hormones (TSH, LH, ACTH, prolactin) did not change in a clinically significant way.2

IGF-1. In the first phase 3 trial, IGF-1 rose by 81.0% with tesamorelin and fell by 5.0% with placebo over 26 weeks .18 After 26 weeks, 47% of people had IGF-1 above 2 standard deviation scores (SDS) and 36% above 3 SDS, a level well above the normal range for their age.2

Fat breakdown and blood sugar. The most prominent metabolic effect of growth hormone in people is a marked increase in the breakdown of stored fat (lipolysis), releasing free fatty acids . The same fatty acids make liver and muscle respond less to insulin, so growth hormone works against insulin.19 That one mechanism explains both the main benefit and the main metabolic risk.

Deep belly fat, not body weight. On CT scans, visceral fat fell while belly fat under the skin and body weight barely changed .22,2 Why visceral fat responds more than fat under the skin is not established. The authors of the liver trial note that the tissue-specific mechanisms “require further study”.23

In detail Why a hormone releaser and not growth hormone itself

Growth hormone and IGF-1 act back on the brain and pituitary. A burst of growth hormone switches on somatostatin and damps GHRH, and IGF-1 adds a slower brake.20,24 Tesamorelin works through this system rather than around it, and growth hormone stays pulsatile on it.17

Researchers have argued that keeping this feedback in place limits side effects compared with giving growth hormone itself .23 We found no published trial that tested this directly. And the brake does not stop IGF-1 from rising far above normal in more than a third of people, as the label shows.2

What the evidence actually shows

Does it work?

Yes, for deep belly fat in people with HIV. It returns after stopping; health benefits are unproven.

Deep belly fat shrank by about 15%

−15.2%

change in deep belly fat in 26 weeks, against +5.0% with placebo

Who took part Phase 3 Study 1: 412 adults with HIV and extra belly fat Source Falutz et al. (2007)18 Evidence Established

The fat grew back after stopping

+22%

growth of deep belly fat in the 26 weeks after switching to placebo (+16% in Study 2)

Who took part Extensions of the two phase 3 trials: 50 and 85 people who stopped after 26 weeks of tesamorelin Source EGRIFTA SV (tesamorelin for injection)2 Evidence Human trials

Body weight did not change

−0.4 kg

average change in body weight in 26 weeks, against 0.0 kg with placebo

Who took part Phase 3 Study 1: 273 adults with HIV on tesamorelin, 137 on placebo Source EGRIFTA SV (tesamorelin for injection)2 Evidence Established

More people reached normal liver fat

35 in 100

had normal liver fat after a year, against 4 in 100 on placebo

Who took part 61 adults with HIV and fatty liver, 12 months, NIH-funded trial Source Stanley et al. (2019)23 Evidence Human trials

These are scan measurements, not illness or death. No published trial has measured heart attacks, strokes or deaths as its main result; the FDA approved tesamorelin without such data.21,2

In detail Every study in one table

14 studies: 11 in humans, 3 in animals, 0 in cells, 0 reviews or other.

Studies discussed on this page
Study Species n Design Funding Research group What it found What it did not show
Jansen et al. 2004 34 Dogs not reported Pharmacokinetic study Industry Originating group In beagle dogs, tesamorelin (then TH9507) was absorbed through the lungs as an inhaled powder; half-life was 26 minutes after an injection under the skin. The paper says it was being developed for age-associated conditions caused by lower growth hormone. Dogs only; number of animals not stated in the abstract; developer-linked authors; the inhaled form was never approved.
Falutz et al. 2007 18 Humans 412 Phase III trial (controlled, blinded) Industry Originating group In 412 adults with HIV and extra belly fat, deep belly fat fell by 15.2% in 26 weeks with tesamorelin and rose by 5.0% with placebo. Triglycerides and the cholesterol ratio improved; IGF-1 rose by 81%. Run by the developer; scan measures, not health outcomes; 26 weeks; mostly men; people treated for diabetes were not included.
Ferdinandi et al. 2007 15 Mixed not reported Animal experiment (controlled) Industry Originating group The hexenoyl group protected the peptide from the enzyme DPP-4 and slowed its breakdown in rat, dog and human plasma. Daily injections raised growth hormone and IGF-1 in pigs, rats and dogs. In studies of up to 4 months, dogs showed reversible liver, kidney and blood changes, put down to long exposure to very high growth hormone and IGF-1. Written by the developer; animal numbers not given in the abstract; the full toxicology data are summarised in the regulatory label, not published here.
Falutz et al. 2008 27 Humans 315 Phase III trial (controlled, blinded) Industry Originating group Of 315 people in the second half-year, those who kept taking tesamorelin kept an 18% lower deep belly fat over 52 weeks; in those switched to placebo, the fat came back. A further 26 weeks only; only people who finished the first phase took part; run by the developer.
Falutz et al. 2010 26 Humans 404 Phase III trial (controlled, blinded) Industry Originating group In a second trial in 404 adults with HIV, deep belly fat fell by 10.9% in 6 months against 0.6% with placebo, and by about 18% after a year of continued use. Distress about belly appearance improved. The gains were rapidly lost after switching to placebo. Run by the developer; smaller effect than in the first trial; scan and questionnaire outcomes, not illness or death.
Stanley et al. 2011 17 Humans 13 Open-label study (uncontrolled) Government Mixed In 13 healthy men, two weeks of daily tesamorelin raised overnight growth hormone, both the peaks and the level between them, and IGF-1 rose by 181 µg/L. Insulin sensitivity measured by clamp did not change. Small, short and without a placebo group; healthy men only; says nothing about long-term use.
Baker et al. 2012 31 Humans 152 Randomised controlled trial (controlled, blinded) Government Independent group In 152 adults aged 55 to 87, 66 of them with mild memory problems, 20 weeks of nightly tesamorelin improved a combined thinking score compared with placebo, mainly on tests of executive function (planning, switching and self-control). IGF-1 more than doubled. Mild side effects were reported by 68% against 36% on placebo. 20 weeks; test scores, not daily life or dementia; gains on single tests were small (about a quarter of a standard deviation); two later, smaller trials in other groups found no clear benefit; one university group, with the drug supplied free by the developer.
Makimura et al. 2012 29 Humans 60 Randomised controlled trial (controlled, blinded) Mixed Mixed In 60 adults with abdominal obesity and low growth hormone, but without HIV, 12 months of tesamorelin lowered deep belly fat (35 cm² against placebo), triglycerides and CRP, and slightly reduced the thickness of the neck artery wall, without changing glucose. Small, one centre; artery-wall thickness and CRP are markers, not heart attacks; not an approved use; the developer paid part of the costs and supplied the drug.
Stanley et al. 2014 28 Humans 50 Randomised controlled trial (controlled, blinded) Government Mixed In 50 adults with HIV and extra belly fat, 6 months of tesamorelin lowered deep belly fat and liver fat compared with placebo. Fasting glucose rose a little in the first 2 weeks, but not over 6 months. Small and short; the authors call it preliminary; liver fat on scans, not liver disease outcomes.
Clemmons et al. 2017 30 Humans 53 Phase II trial (controlled, blinded) Industry Originating group In 53 adults with type 2 diabetes, 12 weeks of tesamorelin did not change insulin response, fasting glucose, HbA1c or overall diabetes control compared with placebo. Run by the developer in 2002 and published 15 years later; small and short; cannot rule out effects over longer use.
Stanley et al. 2019 23 Humans 61 Randomised controlled trial (controlled, blinded) Government Mixed In 61 adults with HIV and fatty liver, a year of tesamorelin lowered liver fat by 4.1 percentage points more than placebo; 35% against 4% reached normal liver fat. Liver scarring (fibrosis) got worse in 2 of 19 against 9 of 24 people on placebo. Small; existing scarring did not improve; two people on tesamorelin stopped because of high blood sugar; a liver-fat endpoint, not liver failure or survival; drug supplied at reduced cost by the developer.
Chege et al. 2024 82 Rats 120 Animal experiment (controlled) Academic Independent group In 120 young rats on a standard or a high-calorie diet, an HIV drug combination given with a high-calorie diet raised blood sugar, blood fats, liver fat and body fat; in the rats also given tesamorelin, these rises were not seen. Rats, not people; 10 rats per group; treatment started together with the HIV drugs, so it says nothing about treating fat that is already there; no specific funding, as the authors state.
Ellis et al. 2025 32 Humans 73 Randomised controlled trial (controlled) Academic Independent group In 73 people with HIV, belly obesity and thinking problems, 6 months of tesamorelin did not improve thinking more than standard care, although waist size fell more. Open-label, no placebo, and too small to rule out a modest effect, as the authors say.
Stewart et al. 2026 33 Humans 22 Randomised controlled trial (controlled, blinded) Mixed Independent group In a placebo-controlled pilot in 22 adults with normal thinking to mild memory problems, 10 weeks of a low dose of tesamorelin did not significantly change thinking, body composition, sleep or fitness. Very small pilot; low dose that did not raise IGF-1; exploratory machine-learning analyses only.

The table lists every study discussed on this page: the developer’s laboratory and animal work, one independent rat study, and every published controlled trial we found of tesamorelin in people. Later analyses of the same trials are cited in the text but not listed again.22,25

In detail The two phase 3 trials, and what happened after stopping

Study 1 and Study 2

The approval rests on two randomised, double-blind, placebo-controlled trials paid for by the developer. People were 18 to 65 years old, had HIV, were on stable HIV treatment and had a large waist; people treated for diabetes were not included.2

  • Study 1 randomised 412 adults (86% men) for 26 weeks. Visceral fat fell by 15.2% with tesamorelin and rose by 5.0% with placebo; triglycerides fell by 50 mg/dL against a rise of 9 . More people on tesamorelin stopped because of an adverse event.18
  • Study 2 randomised 404 adults. Visceral fat fell by 10.9% against 0.6% at six months, and distress about belly appearance improved .26

Pooled, in 806 people, the treatment effect on visceral fat was −15.4%, with no significant change in fat under the skin and no clinically meaningful change in glucose measures at 26 or 52 weeks.22

Stopping

After 26 weeks, people on tesamorelin were randomised again, blind, to continue or to switch to placebo. Those who continued kept a reduction of about 18% at 52 weeks; in those who switched, visceral fat came back .27,26 The label gives the size: visceral fat grew by 22% and 16% in the 26 weeks after switching to placebo in the two trials.2 The effect lasts only while the medicine is used.

What the FDA itself noted

The FDA’s division director wrote that the clear falls in visceral fat “were not accompanied by robust or consistent changes” in people’s body image or in blood fats. She added that data were absent on long-term heart benefit and on the long-term risks of high IGF-1.21

In detail Fatty liver: the most promising newer evidence

Fat in the liver is common in people with HIV and can lead to scarring (fibrosis). One academic group tested whether tesamorelin helps.23

  • In a 6-month trial in 50 adults with HIV and extra belly fat, liver fat fell compared with placebo (a net 2.9 percentage points) ; fasting glucose rose a little in the first two weeks, but not over six months.28
  • In a 12-month trial in 61 adults with HIV and fatty liver, liver fat fell by 4.1 percentage points more than with placebo (37% relative), and 35% against 4% reached normal liver fat . Liver scarring got worse in 2 of 19 people on tesamorelin against 9 of 24 on placebo , but existing scarring did not improve, and two people on tesamorelin stopped because of high blood sugar.23

This is promising and from a well-designed trial with liver biopsies. It is also small, a year long and from one group, and it measured liver fat and scarring, not liver failure or survival. Fatty liver is not an approved use. The authors themselves call for longer studies.23

In detail Outside HIV: obesity, diabetes and the ageing brain
  • Obesity without HIV. In 60 adults with abdominal obesity and low growth hormone, 12 months of tesamorelin lowered visceral fat, triglycerides and CRP, and slightly reduced the thickness of the neck-artery wall, without changing glucose .29 Artery thickness is a marker, not a heart attack.
  • Type 2 diabetes. In a developer-run trial in 53 adults, 12 weeks of tesamorelin did not change insulin response, fasting glucose or HbA1c compared with placebo .30
  • Thinking in older adults. In 152 adults aged 55 to 87, 66 of them with mild memory problems, 20 weeks of tesamorelin improved a combined thinking score against placebo, mainly on tests of executive function (planning, switching between tasks and self-control) . Gains on single tests were small, about a quarter of a standard deviation. Mild side effects were reported by 68% against 36%.31
  • Later thinking trials. In 73 people with HIV and thinking problems, 6 months of tesamorelin did not improve thinking more than standard care .32 A 22-person pilot with a low dose found no significant changes.33
In detail 'Anti-ageing' and body-building claims: outside the evidence

Growth hormone, IGF-1 and GHRH all fall with age.31 In 2004, tesamorelin was being developed for “age-associated conditions resulting from diminished growth hormone (GH) secretion”.34 Already in 2003, a review by researchers who ran such trials concluded that the results so far “do not yet support the routine use” of GHRH in normal ageing.35 What the record shows since then:

  • No trial measured ageing. The trials measured belly fat, liver fat and test scores over months. None measured how long people live, or ageing itself.25,31
  • No information in older people. The label states that there is no information on its use in people over 65.2
  • No strength benefit was shown. In the trials, body weight did not change. Lean mass (everything except fat, including water) rose a little, about 1.4 kg in a pooled analysis, and fell again in people who stopped. No published trial has tested strength or sport performance as its main outcome; one trial of physical function with exercise, in people with HIV, is still running.2,25,36
  • Higher is not shown to be better. Lower growth hormone in older age is common, and no trial has shown that raising it improves health. Raising IGF-1 far above the normal range for years has unknown effects, as the label says.31,2

A test of an idea is not the same as an answer. A benefit on thinking tests in one 20-week trial, not confirmed by two later, smaller trials, is a reason for better trials. It does not show that daily injections help healthy people.31,32,33

In detail Who paid for the evidence

The two approval trials and the diabetes trial were paid for and run by the developer, Theratechnologies.18,26,30 Most later trials come from one group at Massachusetts General Hospital, funded by the US National Institutes of Health. That group is academic, but it is not fully separate from the developer. Its senior author was also the senior author of the phase 3 trial reports, and has been a consultant to the developer and a member of its scientific advisory board.18,23 The developer gave the drug for these trials, paid part of the costs of the obesity trial, and in the 2019 liver trial supplied the drug at reduced cost and received reports of serious adverse events.17,28,29,23 The thinking trials come from three other universities; for two of them, the developer supplied the drug free.31,32,33

The main result has been seen in every trial that measured it. A 2026 meta-analysis of five randomised trials found the same fall in visceral fat.25 The main open questions are not whether it shrinks visceral fat, but whether that improves health, and what it costs in safety over years.

What is genuinely unknown

What is still not known?

Whether it prevents disease, what years of high IGF-1 do, and its safety over many years.
Trials with a placebo lasted one year at most. Two long safety studies were stopped early. Years of use covered by the evidence, counted from the start of treatment.

  • Longest placebo-controlled use (phase 3 extensions)

    52 weeks

  • Liver trial: a year with placebo, then all on tesamorelin

    12 months blinded, then 6 months open

  • Eye trial the FDA required (planned 3 years)

    Not known: stopped in 2018; no results posted

  • Safety study the FDA required (planned 10 years)

    Not known: stopped in 2018; no results posted

Sources Falutz et al. (2008); Stanley et al. (2019); Theratechnologies (2018); Theratechnologies (2018)27,23,37,38 Checked

In detail All open questions, with their sources

As of 22 October 2026, these are specifically unknown:

  • Health benefit. Whether less visceral fat means fewer heart attacks, strokes, liver failure or deaths. The FDA did not require this evidence, and the EU regulator’s committee doubted the benefit was clinically meaningful.21,4
  • Long-term heart safety. The label states that it has not been established.2
  • Years of high IGF-1. “The effects of prolonged elevations in IGF-1 levels are unknown”, says the label.2
  • Cancer. Lifetime cancer studies in rodents were not done. The 10-year safety study whose main outcome was cancer was stopped in 2018 with no results posted.11,38
  • Eyes in diabetes. The 3-year trial of diabetic eye disease (retinopathy) was stopped in 2018 with no results posted.37
  • People over 65, children and pregnancy. There is no information on use over 65. Safety and effect in children have not been established. In pregnancy the label forbids it, based on findings in rats.2
  • Antibodies. About half of people make antibodies to tesamorelin; most of these also recognise the body’s own GHRH. What this means over years has not been reported.2
  • Use outside HIV. Only small, short trials exist.29,30,31
  • What online vials contain. We found no published laboratory analysis of products sold online as tesamorelin.
  • Trials still running. A trial of tesamorelin with exercise in 100 people with HIV is expected to finish in 2028.36

Regulatory status

Is it legal?

Approved in the US. Not approved in the EU, the UK or the Netherlands. Banned in sport.
A prescription medicine in the US, not in the EU. The same trials led to two decisions. Status in the Netherlands, the EU and the US, and in sport, checked on 22 October 2026.
Netherlands and the EUUnited States
Approved as a medicine?No The EU application was withdrawn on 21 June 2012; the Dutch database lists no product4,39Yes Since 10 November 2010, for extra belly fat in adults with HIV1,2
Can a doctor prescribe it?No Not normally. A doctor can ask for a named-patient exemption; the IGJ decides and can refuse6,40Yes On prescription, for the approved use2
Legal to sell a “research” vial?No Supplying a medicine without authorisation is forbidden7No The FDA calls such products unapproved new drugs3
Allowed in sport?No Banned at all times (WADA S2)41No The same worldwide rule41
In detail Status in each country, and in sport
Regulatory status by jurisdiction
Jurisdiction Status Note Checked
European Union Withdrawn Since Application withdrawn on 21 June 2012; the CHMP's provisional view was that it could not be approved. No EU authorisation. 4,46
Netherlands Not authorised Not authorised. Only possible through a named-patient exemption (artsenverklaring), which the IGJ decides on and can refuse. 39,7,6
Germany Not authorised Not authorised. AMG § 73(3) lets a pharmacy import a medicine authorised abroad for one person, on prescription, in narrow cases. 45,46,47
Belgium Not authorised Not authorised. Art. 6quater of the 1964 Medicines Act allows narrow named-patient imports on prescription. 48,46,49
United Kingdom Not authorised Not licensed: the MHRA product database lists no tesamorelin or Egrifta product. 5,50
United States Authorised Since FDA-approved since 10 Nov 2010 (Egrifta; Egrifta SV since 2019, Egrifta WR since 2025). A biological product since 23 Mar 2020. 1,2,11
Sport (WADA) Prohibited in sport · S2, at all times Prohibited at all times under S2 (growth hormone releasing factors); named in the 2026 and 2027 Lists. 41,42

All statuses were checked on 22 October 2026.

Sport (WADA)

The World Anti-Doping Agency’s 2026 Prohibited List names tesamorelin under S2.2.4, growth hormone releasing factors, prohibited at all times. The 2027 List, in force from 1 January 2027, still names it.41,42 Anti-doping laboratories have published methods to detect it in urine.43 In Germany, tesamorelin is also named in the annex of the Anti-Doping Act (Anti-Doping-Gesetz), Germany’s law against doping in sport.44

In detail Two regulators, the same trials, two answers

In May 2010 all 16 voting members of the FDA’s advisory committee backed approval. Several cited powerful testimonies from patients and the lack of any approved treatment. The FDA approved it, but required long-term studies of cancer, diabetic eye disease, diabetes, allergic reactions and heart events.21,8

In Europe, the EMA’s committee (CHMP) came to the opposite provisional view in 2012. It doubted that a smaller belly-fat area brings real health benefit. It also found the trial patients unlike European patients with HIV, who have a lower BMI and less belly fat. It called the rise in IGF-1 a “major safety concern”, because high IGF-1 may be linked to cancer and to worse diabetic eye disease. And it noted that no long-term safety data were provided. The applicant then withdrew.4

Both positions have a cost. People in Europe with this kind of fat gain cannot get tesamorelin as an authorised medicine; whether that pushes some towards unchecked products has not been measured. Equally, the long-term studies the FDA asked for were stopped in 2018 without posted results, so the European committee’s questions are still open.4,38,37

In detail The Netherlands, Germany, Belgium and the United Kingdom

Netherlands

The CBG medicines database lists no tesamorelin or Egrifta product.39 A medicine without a marketing authorisation may not be sold, supplied or imported, with narrow exceptions.7 One exception is the named-patient route (artsenverklaring). The doctor signs a statement that the patient cannot be treated with medicines authorised in the Netherlands, for medical reasons, and takes responsibility. A pharmacy or wholesaler then asks the Health and Youth Care Inspectorate (IGJ) for an exemption. The IGJ decides within eight weeks and can refuse.6,40

Germany

Finished medicines need a German or EU authorisation (AMG § 21); tesamorelin has neither.45,46 A pharmacy may import a small amount of a medicine that is authorised in its country of origin for an individual person, if no identical medicine is available in Germany. From outside the EU or the EEA this needs a prescription (AMG § 73(3)).47

Belgium

A medicine may be placed on the market only with a Belgian or EU authorisation.48 The law allows narrow exceptions, including import by a pharmacist, on prescription, of a medicine authorised in its country of origin when the patient cannot be treated adequately with a medicine on the Belgian market.49

United Kingdom

The MHRA’s product database lists no tesamorelin or Egrifta product.5 Selling or supplying an unauthorised medicine is prohibited.50 An unlicensed medicine can be supplied as a “special” for an individual patient, on the order of a prescriber, to meet clinical needs no licensed medicine can meet.51,52

In detail The United States

Egrifta was approved on 10 November 2010; the 2 mg vial was renamed Egrifta SV in July 2019, and Egrifta WR, a new formulation, was approved on 25 March 2025.1,9,10

At approval the FDA required two long-term safety studies: a 10-year study comparing treated and untreated people, and a 3-year placebo-controlled trial of diabetic eye disease.8 Both appear on ClinicalTrials.gov as terminated in 2018, with 391 and 129 participants, no results posted and no reason given.38,37

Since 23 March 2020 Egrifta has been licensed as a biological product.1 The FDA states that such products are not eligible for the exemptions that let US pharmacies and outsourcing facilities compound medicines.53 In 2026 the FDA sent warning letters to online sellers whose products included tesamorelin. The letters say that, despite “research use only” labels, such products are unapproved new drugs.3

Tesamorelin was not among the seven peptides that the FDA’s Pharmacy Compounding Advisory Committee discussed on 23–24 July 2026.54 That meeting is covered on the BPC-157 page.

Risk profile

What are the risks?

Blood sugar can rise. Joint pain, swelling and sore injection spots are more common. Long-term effects are unknown.
Reactions at the injection spot, muscle pain and swelling were more common than with placebo. People in 100 with each problem in the first 26 weeks of the two phase 3 trials (543 on tesamorelin, 263 on placebo), from the US label.

  • Reaction at the injection spot

    17 in 100 Tesamorelin

    6 in 100 Placebo

  • Joint pain

    13 in 100 Tesamorelin

    11 in 100 Placebo

  • Muscle pain

    6 in 100 Tesamorelin

    2 in 100 Placebo

  • Swollen legs or feet (oedema)

    6 in 100 Tesamorelin

    2 in 100 Placebo

Each square is one person in 100. Source EGRIFTA SV (tesamorelin for injection)2 Evidence Human trials

Unless stated otherwise, risks and frequencies on this page come from the US label, based on 740 people with HIV treated in the trials.2

In detail Blood sugar and diabetes

Growth hormone works against insulin, so more of it can raise blood sugar.19 In the trials, average HbA1c started at 5.3%. HbA1c reached the diabetes range (6.5% or more) in 5% of people on tesamorelin against 1% on placebo (hazard ratio 3.3) . The label asks for a glucose check before starting and regular checks during use.2

In some studies the rise came early. In one trial, fasting glucose rose a little after two weeks but not over six months; the same group describes a modest early worsening of insulin resistance that returned to baseline with longer use.28,23 In the 2019 liver trial, two people on tesamorelin, one with diabetes at the start, had to stop because of high blood sugar.23 People treated for diabetes were excluded from the approval trials.2

In detail IGF-1, growth and cancer: why the label is cautious

Tesamorelin raises growth hormone, which the label calls “a known growth factor”, and IGF-1, which helps cells grow and survive.2,55 That is the reason for the caution:

  1. IGF-1 goes high. After 26 weeks, 36% of people had IGF-1 more than 3 SDS above normal. The label advises checking IGF-1 and considering stopping if it stays high.2
  2. High IGF-1 is linked to some cancers. In observational studies, people with naturally higher IGF-1 had modestly more prostate and premenopausal breast cancer . These studies show a link, not cause.55
  3. Growth signals could feed an existing tumour. The worry is not that tesamorelin starts a cancer, but that a growth signal could help an existing, perhaps undiagnosed, one grow . The label therefore forbids use with active cancer and says to stop at any sign of cancer coming back.2
  4. The long-term answer is missing. No lifetime cancer studies were done in rodents, and the 10-year human safety study was stopped.11,38

The label adds that people with HIV already have a higher background risk of cancer.2 Standard laboratory tests for damage to genes were negative.11 Such tests look for damage to genes; they are not designed to show whether a growth signal helps an existing tumour grow .

Eyes. High IGF-1 may worsen diabetic eye disease (retinopathy). The label asks for regular eye checks in people with diabetes.2,4

In detail Fluid, joints and nerves

Growth hormone makes the body hold on to fluid. The label describes firmer, fuller tissues and aching muscles and joints. This shows up as swelling (oedema), joint pain and carpal tunnel syndrome: numbness and tingling in the hand when a nerve at the wrist is squeezed. These were either short-lived or went away after stopping.2 Tingling or numb skin (paraesthesia) was reported by 5% against 2% on placebo.2 The FDA’s reviewer noted that these are the same kinds of side effects as growth hormone’s, only milder.21

In detail Allergic reactions and antibodies

Allergic (hypersensitivity) reactions, such as itching, redness, flushing, hives and rash, occurred in 4% of people on tesamorelin. The label advises stopping and getting prompt medical help if one is suspected.2

Tesamorelin is a large peptide, and the immune system notices it. Antibodies against tesamorelin were found in 50% of people after 26 weeks; in about 60% of them, the antibodies also recognised the body’s own GHRH . Antibodies that blocked tesamorelin in a laboratory test were found in 10% at 52 weeks. Of people who had antibodies and then stopped, 18% still had them six months later. People with and without antibodies lost similar amounts of visceral fat.2

The label’s warnings section gives a wider figure for injection-site reactions (redness, itching, pain, irritation or bruising): 25% against 14% in the first 26 weeks. It advises changing the injection spot to lower the risk.2

In detail Pregnancy, children, older people and serious illness
  • Pregnancy. Forbidden by the label: less belly fat brings no benefit in pregnancy, and in rats, the offspring developed fluid on the brain (hydrocephaly) at about two to four times the human exposure, and skull bones formed late at lower amounts .2
  • Children and teenagers. Not for use. In children whose bones are still growing it may speed up growth too much.2
  • Over 65. There is no information.2
  • Serious illness. In critically ill people (after open-heart or belly surgery or several injuries, or with sudden breathing failure), more died when they were given growth hormone in medical amounts. The label advises considering stopping tesamorelin in critically ill people.2
  • Pituitary problems. Forbidden after pituitary surgery, a pituitary tumour, radiation to the head or a head injury that affected the pituitary, because the system tesamorelin acts on is damaged.2
In detail Interactions
  • Steroid replacement. Growth hormone lowers the conversion of cortisone into active cortisol. People who take steroid replacement because their adrenal glands do not work may need a higher dose; their doctor decides. Cortisone and prednisone are affected most.2
  • Medicines broken down by liver enzymes (cytochrome P450). Growth hormone may change how fast some of these are cleared, such as steroids, sex hormones, epilepsy medicines and ciclosporin. In tests in healthy people, tesamorelin lowered the levels of simvastatin and ritonavir only slightly (by 15% or less).2
  • Diabetes medicines. Blood sugar can rise, so diabetes treatment may need adjusting.2

Using it safely and legally

How do I use it safely?

The legal route has the fewest unknowns. Check any other product first, and know when to get help.

The authorised medicine is Egrifta, on prescription, in the United States. In the Netherlands a doctor can only request it through the narrow named-patient route.2,6 This section gives no doses: a prescriber decides the dose. A doctor can also check your blood sugar and IGF-1, which matter with this medicine (see talking to your doctor).

The checks below are for any other product, such as a vial sold online as “tesamorelin”.

If your product did not come from a pharmacy: check before you use it

These checks can show that something is wrong. None of them can show that a product is good or free of germs.56,57,58

Tick each box when you have checked it.

  • The seal and the vial are whole

    A broken cap or seal, or a cracked vial, can let germs in. Then do not use it.59,60,61

  • The label shows the name, amount, batch number and expiry date

    In the EU, a medicine must show all four, even on a small vial. If one is missing, or the date has passed, that is a warning sign. Take a photo of the label.62,59

  • For Tesamorelin

    Egrifta comes as two boxes: one with the vials and a patient leaflet, one with the water and syringes. A loose vial is not packed like Egrifta. The pack alone does not prove a product is real.2,11

  • It looks right

    A liquid, or a powder after mixing, should be clear and colourless, with no bits. Is it cloudy, has it changed colour, or do you see bits? Then do not use it.2,63

  • A lab report proves little if:

    • its batch number is not the one on your vial;
    • it does not name the lab, or has no date or signature;
    • it shows only purity (HPLC), with no test of what it is, such as mass spectrometry;
    • it has no test for germs (sterility) or for toxins from germs (endotoxin).

    Even a full report covers only one sample. A report from the seller comes from someone who gains if it looks good. It cannot show that your vial is clean.64,65,66,67,68

    What a certificate of analysis shows, and what it does not

  • It was kept as the label says

    Heat, freezing and sunlight can damage a peptide. Did it arrive warm, or was it frozen? Then do not use it. Often nobody can tell you how it was kept on the way. If you cannot know, you cannot rule out damage. When in doubt, throw it out.63,69,70,61

    When to throw a vial away

  • Clean steps, and a new sterile needle and syringe every time

    Wash your hands and wipe the rubber top with alcohol. Never share a needle, a syringe or a vial.61,71,69

    Sterile technique, step by step

  • Keep the vial, its label and any papers

    Keep them, even when the vial is empty, until you know you feel well. If you need a doctor, bring them. A lab can test what was inside.72,73

    If something goes wrong

  • Tell a doctor, and agree which checks fit you

    A doctor can help you choose blood tests that fit what you use. In the Netherlands, your doctor must keep what you say private.74,75,76

    Which checks matter, and whyTalking to your doctor

  • Know the warning signs before you start

    Spreading redness, fever, a swollen face or hard breathing need help fast. If it is severe, call your local emergency number.77,78,79

    All warning signs, and how fast to act

When to stop and get help

Sources 2, 79, 8, 77, 80

Stop-now warning signs

Call your local emergency number now

  • Confusion or slurred speech, very fast breathing, or pale, blue or blotchy skin, often with fever or shivering These can be signs of sepsis: the body's reaction to an infection has started to damage its own organs.
  • Fainting and not waking up within a minute, or fainting with chest pain, a racing heart or a fit This can be a dangerous heart rhythm or a severe allergic reaction.
  • Pain at the injection spot that is much worse than it looks, or dark, purple or grey patches or blisters there This can be a rare, fast-spreading infection of the deep layers under the skin (necrotising fasciitis).
  • Swelling of the lips, tongue or throat, trouble breathing or swallowing, wheezing, a hoarse voice, or feeling faint, soon after an injection This can be a severe allergic reaction (anaphylaxis), which is life-threatening and gets worse very quickly.

Get medical help today

  • Fever, shivering or feeling very ill in the days after an injection Germs from the needle, the skin or the product may have reached your blood. If you also have a fast heartbeat or fast breathing, call your local emergency number.
  • Redness, heat, swelling or pain around the injection spot that keeps growing or getting worse This can be a skin infection (cellulitis), which needs antibiotics before it spreads.
  • Red lines that run from the injection spot towards the armpit or groin The infection may be spreading along the lymph vessels, and from there into the blood. If you also have a fever with a fast heartbeat or fast breathing, call your local emergency number.
  • A painful, warm lump that fills with pus This is probably an abscess: it often needs draining by a doctor, so do not squeeze it.
  • You were pricked by a needle that someone else had used Blood on a used needle can pass on HIV and hepatitis B or C, and preventive treatment works best within hours.

Stop and contact a doctor

  • You fainted, but woke up quickly and now feel well Fainting is often harmless, but a doctor should check the cause.
  • A new mole, or a mole that changes size, shape or colour, itches or bleeds A changing mole can be skin cancer, and tanning peptides such as melanotan II have been linked to new and changing moles in case reports.
  • A lump at an injection spot that does not go away, or keeps growing A doctor should check whether it is an abscess, a reaction to the product or something else.
  • An itchy, raised rash, or puffy eyes or lips, while breathing stays normal Your body may be reacting to the product, and using it again can bring the reaction back.
In detail The legal route, and why a 'research' vial is not Egrifta

In the US, Egrifta is a prescription medicine from a pharmacy, for one approved use.2 In the Netherlands it is not authorised. A doctor who thinks a patient needs it, and that no authorised medicine will do, can sign a named-patient statement (artsenverklaring). A pharmacy then asks the IGJ for an exemption, which can be refused.6,40 Germany and Belgium have similar narrow routes for medicines authorised abroad.47,49 See legal routes.

Why a “research” vial is a different product

The evidence on this page belongs to Egrifta: a known substance, made under licence, with a label that is kept up to date.2 A vial sold online as “tesamorelin” shares the name but none of those guarantees. The FDA has told sellers of such products that they are unapproved new drugs, whatever the “research use only” label says.3 See product risk.

Even the authorised powder must be mixed before injection, which is a moment when germs can get in. At approval, the FDA named “microbial contamination possibly resulting in soft tissue infections” during mixing as a possible serious risk, and required work on a simpler single-vial product.8 The label says to use the liquid only if it is clear, colourless and free of particles, and never to share a syringe, even with a new needle.2 See sterile technique.

In detail What may be wrong with a vial from outside a pharmacy

The plate shows six things that may be wrong with a vial from outside a pharmacy, from what is in it to what was never tested.

What may be wrong with a vial bought online

Key

  1. May not be what the label says The FDA warns that one name can cover different salt forms, or even a different active substance. A French lab found that products sold as TB-500 did not always match their description.
  2. The amount may differ from the label A 2026 study in Australia tested 3 products sold as retatrutide. They held from about half to almost twice the amount on the label. The TB-500 certificates the FDA saw did not check the amount.
  3. May hold near-copies and leftover chemicals Making a peptide can leave chains that are too short or slightly wrong, plus leftover solvents and other chemicals. Most certificates the FDA saw gave the purity but did not say which impurities were there.
  4. May not be tested for bacterial toxins (endotoxin) For anything injected, the FDA says this test is key. The certificates it saw for BPC-157 and TB-500 did not have it.
  5. May not be tested for germs For injections, the FDA says germ tests are key too. The certificates it saw for BPC-157, KPV and TB-500 showed no germ tests.
  6. Clumps may make immune reactions more likely Peptides can stick together into clumps. The FDA says clumps and impurities may raise the risk of an immune reaction, from harmless to life-threatening. No study has tested this for BPC-157, KPV or TB-500.
In words

The picture shows one small glass vial with a grey rubber stopper and some white powder at the bottom. It has no label. Six numbers show what may be wrong with a vial like this when it is bought online. Number 1, on the glass where a label would be: it may not be what the label says. The FDA warns that one name can cover different salt forms, or even a different active substance. A French lab found that products sold as TB-500 did not always match their description. Number 2, on the powder: the amount may differ from the label. A 2026 study in Australia tested 3 products sold as retatrutide. They held from about half to almost twice the amount on the label. The TB-500 certificates the FDA saw did not check the amount. Number 3, on the powder: making a peptide can leave chains that are too short or slightly wrong, plus leftover solvents and other chemicals. Most certificates the FDA saw gave the purity but did not say which impurities were there. Number 4, inside the vial: it may not have been tested for bacterial toxins, called endotoxin. For anything injected, the FDA says this test is key, and the certificates it saw for BPC-157 and TB-500 did not have it. Number 5, inside the vial: it may not have been tested for germs. For injections the FDA says germ tests are key too, and the certificates it saw for BPC-157, KPV and TB-500 showed no germ tests. Number 6, on the powder: peptides can stick together into clumps. The FDA says clumps and impurities may raise the risk of an immune reaction, from harmless to life-threatening. No study has tested this for BPC-157, KPV or TB-500. That is why number 6 has a different colour: it is a possible risk, not a proven one.

Based on: FDA Briefing Document for BPC-157-Related Bulk Drug Substances (BPC-157 (free base) and BPC-157 acetate), Pharmacy Compounding Advisory Committee meeting, 23–24 July 2026[66]; FDA Briefing Document for KPV-Related Bulk Drug Substances (KPV (free base) and KPV acetate), Pharmacy Compounding Advisory Committee meeting, 23-24 July 2026; FDA Briefing Document for TB-500-Related Bulk Drug Substances (TB-500 (free base) and TB-500 acetate), Pharmacy Compounding Advisory Committee meeting, 23–24 July 2026[67]; Piatkowski et al. (2026); Delcourt et al. (2023)

AI-generated illustration (gpt-image-2.5-sunburst-2026-09-08, 21 October 2026) CC BY 4.0 Image details The picture contains no text; the numbers and labels are added by this site.

In detail Who should not use it, and checks that make sense

Who should not use it, and why

  • Anyone pregnant or trying to conceive, because of the rat findings and because it brings no benefit in pregnancy.2
  • Anyone with active cancer, or a past cancer that is not inactive and fully treated, because growth hormone and IGF-1 are growth signals.2
  • Anyone with pituitary disease, pituitary surgery, head radiation or a head injury that affected the pituitary.2
  • Children and teenagers, whose bones are still growing.2
  • Athletes subject to anti-doping rules, because it is banned at all times.41

Checks that make sense, and why

A doctor can help you choose which of these fit you:

  • Blood sugar or HbA1c before starting and during use, because growth hormone works against insulin and diabetes became more common in the trials.
  • IGF-1 during use, because it went far above normal in more than a third of people, and the label advises considering stopping if it stays high.
  • An eye check if you have diabetes, because high IGF-1 may worsen diabetic eye disease.
  • The cancer screening due for your age, and any unexplained lump checked first, because of the growth-signal effect.
  • A pregnancy test if you could be pregnant, because of the rat findings.

Sources 2, 19, 4

Report side effects

In the Netherlands you can report a side effect to Lareb, the national centre for side effects.81

Sources

Every claim on this page links to one of these sources. Scholarly sources link to their DOI; regulatory sources to the regulator's own page.

In detail All 84 sources, numbered as in the text
  1. U.S. Food and Drug Administration (2026). Drugs@FDA: BLA 022505 (Egrifta, tesamorelin). Regulator accessdata.fda.gov — accessed 22 October 2026 ↩
  2. U.S. Food and Drug Administration / DailyMed (National Library of Medicine) (2026). EGRIFTA SV (tesamorelin for injection): prescribing information and instructions for use. Official product information dailymed.nlm.nih.gov — accessed 20 October 2026 ↩
  3. U.S. Food and Drug Administration (2026). Warning Letters (searchable database). Regulator fda.gov — accessed 22 October 2026 ↩
  4. European Medicines Agency (2012). Egrifta: withdrawal of the marketing authorisation application (EMEA/H/C/002427), with questions and answers (EMA/CHMP/475021/2012). Regulator ema.europa.eu — accessed 22 October 2026 ↩
  5. Medicines and Healthcare products Regulatory Agency (2026). MHRA Products: search results for 'tesamorelin' and 'egrifta'. Regulator products.mhra.gov.uk — accessed 22 October 2026 ↩
  6. Inspectie Gezondheidszorg en Jeugd (IGJ) (2026). Leveren op artsenverklaring. Regulator igj.nl — accessed 22 October 2026 ↩
  7. Staten-Generaal / Koninkrijk der Nederlanden (2007). Geneesmiddelenwet, artikel 40 (verbod op geneesmiddelen zonder handelsvergunning, en de uitzonderingen). wetten.overheid.nl (BWBR0021505), version in force from 9 September 2025. Law wetten.overheid.nl — accessed 22 October 2026 ↩
  8. U.S. Food and Drug Administration (2010). NDA approval letter, NDA 022505 (Egrifta, tesamorelin for injection). Regulator accessdata.fda.gov — accessed 22 October 2026 ↩
  9. U.S. Food and Drug Administration (2019). Supplement approval letter, NDA 022505/S-012 and S-013 (Egrifta and Egrifta SV). Regulator accessdata.fda.gov — accessed 22 October 2026 ↩
  10. U.S. Food and Drug Administration (2025). Supplement approval letter, BLA 022505/S-020 (Egrifta WR). Regulator accessdata.fda.gov — accessed 22 October 2026 ↩
  11. U.S. Food and Drug Administration / DailyMed (National Library of Medicine) (2026). EGRIFTA WR (tesamorelin) for injection: prescribing information, patient information and instructions for use. Official product information dailymed.nlm.nih.gov — accessed 22 October 2026 ↩
  12. Guillemin R, Brazeau P, Böhlen P, Esch F, Ling N, Wehrenberg WB (1982). Growth hormone-releasing factor from a human pancreatic tumor that caused acromegaly. Science 218:585-587. Research article doi:10.1126/science.6812220 ↩
  13. European Bioinformatics Institute (EMBL-EBI) (2026). ChEMBL compound report card: CHEMBL1237026 (tesamorelin). ChEMBL. Dataset ebi.ac.uk — accessed 22 October 2026 ↩
  14. National Center for Biotechnology Information (2026). PubChem Compound Summary for CID 16137828, Tesamorelin. PubChem. Dataset pubchem.ncbi.nlm.nih.gov — accessed 22 October 2026 ↩
  15. Ferdinandi ES, Brazeau P, High K, Procter B, Fennell S, Dubreuil P (2007). Non-clinical pharmacology and safety evaluation of TH9507, a human growth hormone-releasing factor analogue. Basic & Clinical Pharmacology & Toxicology 100:49-58. Research article doi:10.1111/j.1742-7843.2007.00008.x ↩
  16. U.S. Food and Drug Administration (Electronic Code of Federal Regulations) (2026). 21 CFR 600.3 – Definitions, paragraph (h)(6): 'protein'. eCFR. Law ecfr.gov — accessed 22 October 2026 ↩
  17. Stanley TL, Chen CY, Branch KL, Makimura H, Grinspoon SK (2011). Effects of a growth hormone-releasing hormone analog on endogenous GH pulsatility and insulin sensitivity in healthy men. The Journal of Clinical Endocrinology and Metabolism 96:150-158. Research article doi:10.1210/jc.2010-1587 ↩
  18. Falutz J, Allas S, Blot K, Potvin D, Kotler D, Somero M, et al. (2007). Metabolic effects of a growth hormone-releasing factor in patients with HIV. The New England Journal of Medicine 357:2359-2370. Clinical trial doi:10.1056/NEJMoa072375 ↩
  19. Møller N, Jørgensen JO (2009). Effects of growth hormone on glucose, lipid, and protein metabolism in human subjects. Endocrine Reviews 30:152-177. Review doi:10.1210/er.2008-0027 ↩
  20. Veldhuis JD, Anderson SM, Shah N, Bray M, Vick T, Gentili A, et al. (2001). Neurophysiological regulation and target-tissue impact of the pulsatile mode of growth hormone secretion in the human. Growth Hormone & IGF Research 11 Suppl A:S25-S37. Review doi:10.1016/s1096-6374(01)80005-8 ↩
  21. Parks MH (U.S. Food and Drug Administration, Center for Drug Evaluation and Research) (2010). Division Director Summary Review, NDA 22-505 (Egrifta, tesamorelin acetate). Regulator accessdata.fda.gov — accessed 22 October 2026 ↩
  22. Falutz J, Mamputu JC, Potvin D, Moyle G, Soulban G, Loughrey H, et al. (2010). 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. The Journal of Clinical Endocrinology and Metabolism 95:4291-4304. Meta-analysis doi:10.1210/jc.2010-0490 ↩
  23. Stanley TL, Fourman LT, Feldpausch MN, Purdy J, Zheng I, Pan CS, et al. (2019). Effects of tesamorelin on non-alcoholic fatty liver disease in HIV: a randomised, double-blind, multicentre trial. The Lancet HIV 6:e821-e830. Clinical trial doi:10.1016/S2352-3018(19)30338-8 ↩
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