Peptide guide

Tesamorelin

A synthetic GHRH analog, sold as Egrifta, that prompts the body's own growth hormone release and is approved for reducing visceral fat in HIV-associated lipodystrophy.

Tesamorelin is a lab-made copy of growth hormone-releasing hormone that nudges the pituitary to put out more of the body's own growth hormone. It's one of the few peptides in this space with real FDA approval, sold as Egrifta for HIV-associated lipodystrophy, where it shrinks deep abdominal fat. The research-grade material sold online isn't that approved product, and the lean-out and anti-aging uses people chase aren't approved or proven. People still run it daily, so the practical questions are how to prepare it correctly and how to tell a real source from a scam.

By the Zapify Research team

Reviewed against 10 clinical & research sources · Updated June 2026 · Educational use only

Type: 44-aa GHRH analog
Route: Subcutaneous
Typical dose: 1–2 mg/day
Cycle: Daily, eveningoften 5 on / 2 off
Storage: Mixed: ~4 wksSealed: months
Status: Approved for HIV onlynot for general use

What is Tesamorelin?

A synthetic GHRH copy that tells your own pituitary to release more growth hormone; FDA-approved as Egrifta for HIV-lipodystrophy, but the research-grade powder isn't that product.

Tesamorelin is a synthetic copy of growth hormone-releasing hormone, the signal your hypothalamus normally sends to tell the pituitary gland to release growth hormone. It's a 44-amino-acid peptide built from the natural GHRH(1-44) sequence, with one chemical cap added at the front, a trans-3-hexenoic acid group, that keeps your enzymes from chewing it up in minutes. That single modification is most of what separates it from the natural hormone.

Because it works upstream, it doesn't add growth hormone to your body the way injected HGH does. It tells your own pituitary to make more, so the hormone still comes out in natural pulses rather than a flat synthetic flood. The downstream marker that rises is IGF-1, the longer-lived signal most of growth hormone's effects run through.

It's sold under the brand name Egrifta, and in March 2025 a reformulated, more concentrated version, Egrifta WR, was approved. The powder sold by research-chemical vendors carries the same name but isn't the same product: no diluent kit, no pharmacy quality control, and none of the approval behind it.

Tesamorelin is FDA-approved, but for one narrow use: reducing excess visceral abdominal fat in adults with HIV-associated lipodystrophy. That's the only approved indication. The fat-loss, recovery, and anti-aging uses people buy research-grade tesamorelin for are off-label and unapproved, and the research-chemical powder is not the approved medicine. Treat it as a prescription drug being used outside its lane, not a proven supplement.

What is it studied for?

Two Phase 3 trials in about 806 HIV-lipodystrophy patients cut visceral fat ~15% over 26 weeks, but that human evidence sits in one population for one problem.

Tesamorelin has something most peptides in this market don't: completed, published human trials. Its approval rests on two Phase 3 studies pooling about 806 participants with HIV-associated lipodystrophy, where it cut visceral adipose tissue by roughly 15% against placebo over 26 weeks. The catch is narrow scope. That human evidence sits almost entirely in one population, for one problem, and the popular uses reach well past it.

Human evidence, by use

Phase 3, approvedHIV-associated visceral fat

No approval trialsGeneral fat loss & anti-aging

The research and clinical interest has clustered in a few areas:

Visceral fatThe approved use. Deep abdominal fat around the organs fell measurably in HIV patients, and that's where the strongest data sits.

Liver fatTrials in HIV patients showed reductions in liver fat and in NAFLD, an effect tied to the visceral-fat changes.

GH / IGF-1 axisIt reliably raises growth hormone and IGF-1, which is why it draws interest for recovery and body composition outside the approved label.

The mechanism is well understood, more so than for most research peptides. Tesamorelin binds the GHRH receptor on the pituitary and stimulates pulsatile growth hormone release, and the stabilizing cap stretches its working half-life to roughly half an hour, around 26 to 38 minutes, versus only a few minutes for natural GHRH. What's far less settled is whether the visceral-fat benefit in a metabolically unusual HIV population transfers to a healthy person using it to lean out. That question hasn't been run as a trial.

Why people use it

People target deep belly fat or growth-hormone-linked recovery and trust an FDA-approved molecule, yet no trial has tested it for fat loss or anti-aging in healthy adults.

Most people who try tesamorelin outside its approved use are reaching for one of a few things. These are the reasons they pick it up, not evidence it delivers for them:

Targeting stubborn deep belly fat, since the one thing it's actually proven to do is shrink visceral fat, even if that proof comes from a different population.
Wanting the benefits people associate with raised growth hormone, sleep quality, recovery, body composition, without injecting HGH directly.
Preferring a peptide that nudges the body's own pulsatile release rather than overriding it with synthetic hormone.
Trusting that an FDA-approved molecule has a cleaner safety record than the average gray-market research peptide, which is partly fair.

No trial has tested tesamorelin for general fat loss or anti-aging in healthy adults, and its proven benefit comes from a population with a specific metabolic disorder. What it does have is real human safety and efficacy data, a clean and well-mapped mechanism, and an established prescription pedigree, which is more than almost anything else in this category can claim. That makes it a more reasonable thing to be curious about. It doesn't make the off-label result a sure thing, and it won't substitute for the basics that move visceral fat with actual evidence: sleep, training, and diet.

How to reconstitute Tesamorelin

Mix a multi-dose research vial with bacteriostatic water, swirl don't shake; a 10 mg vial in 5 mL gives 2 mg/mL, so 50 units is 1 mg and 100 units is 2 mg.

Tesamorelin arrives as a freeze-dried powder that has to be mixed into liquid before use. The approved Egrifta product ships with its own diluent kit and clear instructions; the current Egrifta WR version is reconstituted with bacteriostatic water about once a week and dosed daily from that vial. Research-grade vials come bare, with no kit and no instructions, and people handle them like other multi-dose peptides, which changes what you mix with and how carefully you have to work.

Step 1Start with powderWipe the rubber stopper with an alcohol swab.

Step 2Add bac. waterRun it slowly down the inside wall — never shake.

Step 3Draw your doseThe calculator gives the exact units to draw to.

Wipe the rubber stopper with an alcohol swab first, every time.
For a multi-dose research vial, use bacteriostatic water, not plain sterile water and not saline. The trace of benzyl alcohol in it holds back bacteria, which matters because you'll be drawing from the same vial across many days. (This is the same reason the current branded product, Egrifta WR, uses bacteriostatic water for its weekly reconstitution.)
Add the water slowly, running it down the inside glass wall. Don't blast it straight onto the powder.
Don't shake it. Swirl gently and let it dissolve on its own. Shaking foams the solution and can damage the peptide.

A common setup for a 10 mg vial is 5 mL of bacteriostatic water, which gives 2 mg/mL. On a U-100 insulin syringe, 50 units is then 1 mg and 100 units is 2 mg. The water doesn't change how much peptide is in the vial; it only sets the concentration, which decides how many units you draw. More water means a more dilute mix and a bigger draw for the same dose. You can't ruin it with too much or too little, you only change the draw math, and that's exactly what the calculator handles.

Calculate your exact Tesamorelin reconstitution →

Dose & units

The approved HIV dose is 2 mg under the skin once daily; off-label protocols report roughly 1–2 mg daily, usually injected in the evening, with milligram—not microgram—amounts.

The approved dose of tesamorelin exists only for HIV-associated lipodystrophy and is set by a prescriber who monitors your IGF-1 and glucose. It was 2 mg subcutaneously once a day in the original Egrifta and the pivotal trials; the newer Egrifta SV and Egrifta WR deliver a bioequivalent dose at a smaller volume (1.4 mg and 1.28 mg). There is no approved self-dose for fat loss or anti-aging. Everything below is what clinics and protocols report, not a medical standard. Decide what goes into your body with a licensed provider, not with this page.

Typical range

The dose used in the approval trials was 2 mg per day injected under the skin of the abdomen. Off-label protocols report a range of roughly 1 to 2 mg daily, with many starting at 1 mg. A microgram is a thousandth of a milligram, so tesamorelin's milligram doses are far larger than the microgram doses of peptides like BPC-157, don't carry the numbers across.

Timing

Most protocols put the injection in the evening or at bedtime, to ride alongside the body's natural nighttime growth hormone pulse. The trials weren't strictly bedtime-only, and consistency from day to day matters more than the exact hour.

Cycling

Tesamorelin is taken daily rather than in on/off blocks the way recovery peptides are, and the HIV trials ran it continuously for 26 weeks and beyond. Some off-label protocols add a weekly rest, commonly a 5-days-on, 2-days-off pattern, on the theory that it keeps receptors responsive, though that's a practice rather than a trial-backed finding.

On5 days

Off2 days

For the exact mark to draw to on your insulin syringe, don't eyeball it. The calculator turns your vial size, water, and dose into the precise number of units.

Get your exact units →

Storage

Sealed powder lasts months; a research vial mixed with bacteriostatic water keeps refrigerated at 2–8 °C for about 4 weeks — but branded products follow their own labeled handling.

Sealed & drySealed freeze-dried powder stays stable for months and tolerates shipping.

ReconstitutedA research vial mixed with bacteriostatic water keeps at 2–8 °C for about 4 weeks; don't freeze, keep out of light, and toss if cloudy or discolored.

The branded product follows its own labeled handling, not this rule of thumb. Egrifta WR is reconstituted with bacteriostatic water and, per its label, kept refrigerated and used within a set window across its weekly multi-dose period; the older daily-reconstitution formulations were mixed fresh from sterile water and used right away. A research vial leans on the preservative in bacteriostatic water to stay clean across repeated draws, so always follow the instructions that come with an approved product rather than applying a generic timeline to it.

That four-week limit is about contamination, not potency, the peptide itself often stays good well beyond it. Reconstitute with plain sterile water instead of bacteriostatic and you drop to roughly a day, since there's no preservative holding bacteria back.

Don't freeze a reconstituted vial, keep it out of direct light, write the mix date on the label, and throw it out if the solution ever turns cloudy or discolored, whatever the date says.

Side effects & safety

Injection-site reactions hit ~25% and IGF-1 rose ~80%, with higher glucose intolerance and new-onset diabetes; it's contraindicated in active cancer, pituitary tumors, and pregnancy.

Tesamorelin has a real human safety record from its trials, which is more than most peptides here offer. Most of what it causes traces directly to raised growth hormone and the fluid shifts that come with it.

Most common: injection-site reactions, redness, itching, pain, or bruising, reported in around 25% of users versus 14% on placebo in trials, rarely bad enough to stop treatment.
Fluid-related: joint pain, swelling in the limbs, muscle aches, and tingling or numbness, all consistent with elevated growth hormone.
Metabolic: IGF-1 rose roughly 80% on average, and the FDA flagged a higher rate of glucose intolerance and new-onset diabetes (about 5% vs 1% reaching an HbA1c of 6.5% or above) over the program.
Rare: hypersensitivity reactions including hives and flushing, reported in around 4% of patients, with a single case of anaphylaxis in trials.

Don't use tesamorelin if you have an active cancer, a pituitary tumor or prior pituitary irradiation or surgery, or if you're pregnant. The raised IGF-1 that drives the benefit can also feed existing tumor cells, which is why active malignancy is a hard contraindication, and animal studies showed fetal harm, so it's contraindicated in pregnancy (the older labeling called this Pregnancy Category X). Anyone with diabetes or blood-sugar issues should only use it under monitoring, since it nudges glucose upward.

If you compete, tesamorelin is prohibited. As a GHRH analog it falls under WADA's S2 category, banned both in and out of competition, and the IGF-1 rise it produces can itself flag the growth-hormone biomarker test. A positive is a doping violation.

And the biggest risk with a research-grade vial isn't the molecule, which is well characterized. It's whether the powder you bought is actually tesamorelin, at the strength on the label. That comes down to where you buy it.

How to vet a source

Because an FDA version exists, gray-market powder is easy to dress up, so insist on a batch-specific, third-party COA whose lot number matches your vial.

Tesamorelin is unusual here because an FDA-approved version exists, which makes the gray-market powder easy to dress up as something it isn't. Research-chemical vendors sell it unregulated, and a real share of independently tested peptide vials come back underdosed, impure, or not even the labeled compound, a 44-amino-acid sequence you can't verify by looking at the powder. Where you buy matters more than almost anything else. The one document that separates a real seller from a gamble is a certificate of analysis: a third-party lab's report on what's actually in the vial.

A real COA shows

An identity test (usually mass spectrometry) confirming the peptide is what the label says.
A purity figure from HPLC, typically 98% or higher.
A lot or batch number that matches the number printed on your vial.
A named, independent accredited lab and a recent test date.

Walk away if

There’s no COA, or it’s a generic image with no lot number.
The “certificate” comes from the seller instead of a third-party lab.
The lot number doesn’t match your vial, or there isn’t one at all.
It’s a flat image you can’t trace back to the lab that issued it.

That's the standard worth holding any seller to, ours included. Ask for the batch-specific COA before you buy, match the lot number to your vial, and don't accept a screenshot in place of a traceable report.

See the Zapify compound catalog →

Common questions about Tesamorelin

Is tesamorelin FDA-approved?

Yes, but narrowly. It's approved as Egrifta to reduce excess visceral abdominal fat in adults with HIV-associated lipodystrophy, and that's the only approved use. A reformulated, more concentrated version, Egrifta WR, was approved in March 2025. Using it for general fat loss, recovery, or anti-aging is off-label, and the research-grade powder sold online isn't the approved product at all.

How is tesamorelin different from injecting HGH?

Tesamorelin works one step upstream. Instead of putting synthetic growth hormone into your body, it signals your own pituitary to release more, so the hormone still comes out in natural pulses. Injected HGH overrides that rhythm with a steady external supply. The practical trade-off is that tesamorelin depends on a pituitary that can still respond, which is why it's contraindicated in people with pituitary tumors or damage.

Does the visceral-fat result apply to healthy people trying to lean out?

That hasn't been tested. The proven visceral-fat reduction of roughly 15% comes from two Phase 3 trials in people with HIV-associated lipodystrophy, a population with a specific metabolic disorder. Whether the same effect shows up in a healthy adult using it off-label is an open question, not a settled one. Anyone presenting it as a guaranteed fat-loss tool is going past the data.

What water should I reconstitute a research vial with?

For a multi-dose research vial you draw from over weeks, use bacteriostatic water. Its trace of benzyl alcohol holds back bacteria between draws, which plain sterile water doesn't. This is the same reason the current branded product, Egrifta WR, uses bacteriostatic water for its weekly reconstitution. If you only had sterile water, the mix would need to be used within about a day. Match the water to how the vial is actually used, and follow the labeled instructions on any approved product.

Will tesamorelin show up on a drug test?

For competitive athletes, yes, it's a problem. Tesamorelin is on WADA's S2 list, prohibited both in and out of competition. Beyond direct detection, the roughly 80% rise in IGF-1 it produces can flag the growth-hormone biomarker test on its own. A positive result is an anti-doping violation.

References

This page is for research and educational purposes only. It is not medical advice or a recommendation to use any compound. The dose ranges shown are reported by clinics and research literature, not validated medical standards, and Tesamorelin is not FDA-approved. Talk to a licensed medical provider about anything you put in your body.