Tesamorelin
Also known as Egrifta, Egrifta SV, Egrifta WR, TH9507
Tesamorelin is a stabilized growth hormone releasing hormone analog approved as Egrifta to reduce belly fat in people with HIV-related lipodystrophy. It is the GHRH analog with the strongest human evidence, and people use it off-label for visceral fat loss and general growth hormone support.
Overview
Tesamorelin is the full 44 amino acid human GHRH sequence with a trans-3-hexenoic acid group attached to the N-terminus. That small modification protects it from DPP-IV cleavage and roughly doubles its stability in blood compared to native GHRH. It was developed by Theratechnologies and approved by the FDA in 2010 under the brand name Egrifta for reducing excess abdominal fat in HIV patients with lipodystrophy. Newer formulations (Egrifta SV and Egrifta WR) deliver the same drug with a more concentrated solution and a simpler reconstitution.
The approval rests on two large placebo controlled Phase 3 trials with over 800 participants. Daily 2 mg injections reduced visceral adipose tissue by about 15 to 18 percent over 26 weeks, with modest improvements in triglycerides and patient reported body image. The fat came back when the drug was stopped. IGF-1 rose into the upper normal range, and glucose metabolism was largely unchanged, though the label warns to monitor it. Later studies looked at liver fat in people with nonalcoholic fatty liver disease and found reductions in hepatic fat and slowed fibrosis progression.
For people outside the HIV context, tesamorelin is attractive because its efficacy is documented in real trials rather than inferred from mechanism. A trial in older adults with and without mild cognitive impairment reported improved executive function, which has fueled interest in it as a cognitive aid, but that finding has not been replicated at scale. The main practical limitations are cost and the fact that the visceral fat loss is moderate and requires ongoing use.
How it works
Tesamorelin activates the GHRH receptor on pituitary somatotrophs, prompting synthesis and pulsatile release of growth hormone. Elevated growth hormone increases lipolysis in adipose tissue, with visceral fat being especially responsive, and drives hepatic IGF-1 production. Because it works through the pituitary rather than replacing growth hormone directly, the negative feedback loop stays intact, which is why IGF-1 rises but rarely overshoots into the range seen with exogenous growth hormone. The N-terminal modification slows enzymatic degradation, giving each injection a longer window of receptor activity than native GHRH.
What the research shows
- human RCTDaily 2 mg tesamorelin reduced visceral adipose tissue by roughly 15-18 percent over 26 weeks in HIV lipodystrophy versus placebo.
- human RCTTesamorelin reduced liver fat and slowed progression of fibrosis in HIV patients with nonalcoholic fatty liver disease over 12 months.
- human RCTIn healthy older adults and those with mild cognitive impairment, 20 weeks of tesamorelin improved executive function scores.
- human RCTVisceral fat returned toward baseline within 6 months of discontinuing treatment.
- human pilotTesamorelin increased IGF-1 while preserving pulsatile growth hormone secretion in healthy volunteers.
Evidence labels: rodent and in vitro mean no human data for that finding. Human pilot means small, often uncontrolled. Human RCT means randomized and controlled. Clinical means an approved drug with regulatory data.
Dose calculator
U-100 insulin syringeUnits are a volume on the syringe, not an amount of peptide. Concentration changes every time you change the water volume. The standalone calculator explains the math.
Dosing and protocol
2 mg daily is the approved dose; some community protocols use 1 mg to reduce cost or side effects
Ongoing; benefits reverse after stopping. Reassess with IGF-1 and waist measurements at 3-6 months.
Bedtime on an empty stomach is most common; the label allows any time of day. Abdominal injection sites, rotated.
| Vial | Suggested water | Concentration | Low dose draw |
|---|---|---|---|
| 5 mg | 1 mL | 5 mg/mL | 20 units |
| 10 mg | 2 mL | 5 mg/mL | 20 units |
| 20 mg | 3 mL | 6.667 mg/mL | 15 units |
Lyophilized: fridge or freezer, away from light. Reconstituted: fridge 2-8C, use within 4 weeks.
Cautions
- ▲Injection site redness, itching, and bruising are the most common complaints; rotate sites.
- ▲Joint pain, swelling in the hands and feet, and carpal tunnel symptoms can occur from fluid retention.
- ▲Can raise blood glucose in susceptible people; check fasting glucose and HbA1c periodically.
- ▲Contraindicated in active malignancy, pregnancy, and anyone with a disrupted hypothalamic-pituitary axis from surgery or radiation.
- ▲Fat loss is real but moderate and reverses when you stop; it is not a substitute for diet.
Commonly stacked with
Frequently asked
Is tesamorelin the same as growth hormone?
No. It tells your pituitary to make more of your own growth hormone rather than supplying it from outside. That keeps the body's feedback loop intact, which is why IGF-1 usually lands in the upper normal range rather than far above it.
How much fat can I expect to lose?
In the approval trials, people lost about 15 to 18 percent of their visceral fat over six months, which translated to a couple of centimeters off the waist. Subcutaneous fat changed very little. Results outside the HIV population are less documented but seem to follow the same pattern.
Does it need to be taken forever?
The fat that comes off returns within months of stopping, so most people either continue at a maintenance dose or accept that the effect is temporary. There is no data on intermittent cycling.
Can I take it if I have prediabetes?
Use caution. Growth hormone opposes insulin, and while the trials showed only small glucose changes, the label recommends monitoring. Anyone with impaired fasting glucose should be checking bloodwork regularly.
References
- Tesamorelin, a growth hormone-releasing factor analog, in HIV-infected patients with excess abdominal fat: pooled analysis of two Phase 3 trials. Journal of Acquired Immune Deficiency Syndromes, 2010
- Effects of tesamorelin on nonalcoholic fatty liver disease in HIV: a randomised, double-blind, multicentre trial. The Lancet HIV, 2019
- Growth hormone-releasing hormone effects on brain GABA levels in mild cognitive impairment and healthy aging. JAMA Neurology, 2014
- Egrifta (tesamorelin for injection) prescribing information. US Food and Drug Administration, 2010