THE SECRETAGOGUES COMPARED
Tesamorelin Explained — The FDA-Approved GHRH Analog for Visceral Fat
By G1 Peptides · Medically reviewed by the G1 Peptides clinical team · Updated September 24, 2026 · 2 min read
THE SHORT ANSWER
Tesamorelin is a synthetic GHRH analog and the only growth-hormone-releasing peptide with FDA approval. In year-long controlled trials it reduced visceral abdominal fat by roughly 15–18% while sparing subcutaneous fat, and improved triglycerides. It is dosed at 1–2 mg daily by subcutaneous injection, with joint aches, fluid retention, and injection-site reactions as the main side effects.
What it is
Tesamorelin is the 44-amino-acid GHRH molecule with a modification at the N-terminus that protects it from rapid breakdown, giving it a stronger and longer action at the pituitary than sermorelin. It was approved by the FDA in 2010 as Egrifta for the reduction of excess abdominal fat in HIV-associated lipodystrophy, and it is prescribed off-label — and compounded — for visceral fat and body composition more broadly.
The evidence
Two 26-week randomized trials, extended to 52 weeks, tested 2 mg daily against placebo in over 800 patients (Falutz 2007 and the pooled analyses that followed):
- Visceral fat fell by about 15–18% by CT scan at 26 weeks, and the reduction was maintained through 52 weeks on treatment.
- Subcutaneous fat and total weight changed little — the effect was selective.
- Triglycerides fell; total and non-HDL cholesterol improved modestly.
- IGF-1 rose, confirming the mechanism, and stayed within the normal range for most.
- On stopping, visceral fat returned toward baseline within 26 weeks.
Smaller studies since have reported improvements in liver fat and in some cognitive measures in older adults; those are promising but less established.
Dosing
The approved dose is 2 mg once daily by subcutaneous injection into the abdomen. Compounded protocols sometimes use 1–1.5 mg, or pair a lower dose with ipamorelin. Timing follows the secretagogue rule — away from meals, often at bedtime.
Compounded tesamorelin is a lyophilized vial; G1 supplies 10 mg. In 2 mL that is 5 mg/mL, so a 2 mg dose is 40 units and the vial holds five doses. The tesamorelin calculator handles other combinations and flags draws that exceed one syringe. It is also in the TesaTrim (with AOD-9604) and Fragment Apex (with CJC-1295/ipamorelin) pens.
Side effects
The trials' most common effects were injection-site reactions (redness, itching, bruising), joint pain, swelling in the hands and feet, muscle aches, and tingling — the standard signs of growth hormone signalling, generally mild and dose-related. A minority saw glucose rise, which is why providers check fasting glucose and HbA1c. Hypersensitivity reactions occurred rarely.
Who it suits
Someone whose primary goal is visceral fat and metabolic markers — a waist that will not move, elevated triglycerides, fatty liver — rather than general weight loss, and who is comfortable with daily injections and a higher-cost compound. For general body composition and recovery, a CJC-1295/ipamorelin protocol is usually the first choice; for visceral fat specifically, tesamorelin has the evidence.
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FREQUENTLY ASKED
Does tesamorelin help with fat outside the belly?
Its measured effect is specifically on visceral (deep abdominal) fat; subcutaneous fat and total weight changed little in trials. That specificity is the point — visceral fat is the metabolically harmful kind — but it is not a general weight-loss drug.
What happens when I stop?
In the trials, visceral fat returned toward baseline within six months of stopping. Like most hormonal signals, the effect lasts as long as the signal does, so providers discuss maintenance or cycling rather than a fixed course.
Is tesamorelin safe for people with diabetes?
It caused small increases in glucose and HbA1c in some trial participants, so providers monitor glucose and use it cautiously in diabetes. It is not used in uncontrolled diabetes or in active proliferative retinopathy.
This article is educational and is not medical advice. Peptides are prescription medications; whether any of them is appropriate for you is a decision for a licensed provider who knows your history.