Tesamorelin

Tesamorelin is a laboratory-made version of growth hormone-releasing hormone (GHRH), the signal your hypothalamus sends to the pituitary gland telling it to release a pulse of growth hormone (GH). It uses the full 44-amino-acid human sequence, with a small fatty tail called a trans-3-hexenoyl group attached to the tyrosine at one end; that tail is what stops blood enzymes from chewing the molecule up as fast as they destroy natural GHRH. Unlike most compounds covered on this site, it is a real approved medicine. The US Food and Drug Administration (FDA) approved it as Egrifta on 10 November 2010 for the reduction of excess abdominal fat in adults living with human immunodeficiency virus (HIV) who have lipodystrophy, a body-fat redistribution problem linked to older antiretroviral drugs. It has since been reformulated twice, as Egrifta SV in 2019 and as Egrifta WR (tesamorelin F8) in March 2025. The approved label says in plain words that it is not indicated for weight loss management and that long-term cardiovascular safety has not been established, so the physique and general belly-fat uses people buy it for all sit outside what any regulator has cleared.

• Its one approved use: shrinking excess visceral abdominal fat in adults with HIV who have lipodystrophy, taken as a daily injection under the skin of the abdomen
• Reducing liver fat in HIV-associated non-alcoholic fatty liver disease. This has been tested in a randomised trial but is not on the FDA label
• Off-label visceral fat reduction in people without HIV. The one 12-month randomised trial in HIV-negative abdominally obese adults with reduced growth hormone secretion found visceral fat fell while fat under the skin did not
• Off-label body-composition work in gyms and clinics, on the reasoning that it raises your own growth hormone rather than injecting growth hormone. No trial has tested it in healthy trained adults
• Cognition in ageing, which was studied in a 20-week randomised trial in older adults with and without mild cognitive impairment. A later 6-month trial in people with HIV found no clear cognitive benefit

Your pituitary holds growth hormone the way a tap holds water, and GHRH is the hand that turns it. Natural GHRH gets broken down in the bloodstream within a couple of minutes, so the hand barely gets a grip. Tesamorelin is the same hand with a non-slip coating: the added fatty group makes it last long enough to actually turn the tap. The extra growth hormone then goes to work on fat stores, and the deep fat packed around your organs turns out to be the most responsive to it.

1. First doseGrowth hormone rises quickly. The peptide itself peaks in blood about nine minutes after the injection and has a mean elimination half-life of roughly eight minutes for the Egrifta SV formulation, so the drug is gone long before its effect is; less than 4 percent of a subcutaneous dose reaches the bloodstream intact (FDA Egrifta SV label, 2019).
2. Week 2-13Insulin-like growth factor 1 (IGF-1), the downstream marker, climbs. The label records IGF-1 above 2 standard deviation scores appearing as early as 13 weeks, and by 26 weeks 47 percent of treated patients were above 2 standard deviation scores and 36 percent above 3 (FDA Egrifta SV label, 2019).
3. Week 26This is the primary endpoint in nearly every trial. In the 412-person phase 3 trial, visceral adipose tissue fell 15.2 percent on tesamorelin while rising 5.0 percent on placebo, triglycerides fell about 50 mg/dL, and the ratio of total cholesterol to HDL improved (Falutz et al., 2007).
4. Month 6-12Effects hold while you keep injecting, and liver fat responds on this timescale. Over 52 weeks visceral fat stayed about 18 percent below baseline (Falutz et al., 2008). In the 61-person liver trial, 12 months cut hepatic fat fraction by an absolute 4.1 percent versus placebo and 35 percent of treated people got below the 5 percent threshold, against 4 percent on placebo (Stanley et al., 2019).
5. Post-cycleThe fat comes back. In the 52-week extension study, patients switched from tesamorelin to placebo at week 26 reaccumulated visceral adipose tissue (Falutz et al., 2008). The approved product is taken continuously, not in the 12-weeks-on, 4-weeks-off pattern on this cheatsheet, and no trial has tested cycling it.

• Injection site reactions, reported in 25 percent of treated patients versus 14 percent on placebo during the first 26 weeks: redness, itching, pain, irritation and bruising (FDA Egrifta SV label, 2019).
• Fluid-retention effects driven by the growth hormone rise: joint pain in 13 percent versus 11 percent on placebo, pain in an extremity 6 percent versus 5 percent, muscle pain 6 percent versus 2 percent, peripheral swelling 6 percent versus 2 percent, and carpal tunnel syndrome in about 1 percent of treated patients versus none on placebo (FDA Egrifta SV label, 2019).
• Pins and needles (paresthesia, 5 percent versus 2 percent) and reduced sensation (hypoesthesia, 4 percent versus 2 percent).
• Glucose intolerance. In the trials, 5 percent of tesamorelin patients versus 1 percent on placebo reached an HbA1c of 6.5 percent or higher by week 26, an intention-to-treat hazard odds ratio of 3.3 (95 percent confidence interval 1.4 to 9.6) for developing diabetes (FDA Egrifta SV label, 2019). Several individual trials separately reported no significant glucose change over 6 to 12 months, so this is a real but not universal signal.
• Hypersensitivity reactions in 4 percent of treated patients, including itching, redness, flushing, hives and rash; 21 people discontinued the pivotal trials because of them.
• Antibodies. Anti-tesamorelin IgG antibodies were detected in 50 percent of patients at 26 weeks and 47 percent at 52 weeks, and in 85 percent of those who had a hypersensitivity reaction. About 60 percent of those antibodies cross-reacted with the body's own GHRH. Fat loss and IGF-1 response were similar with or without antibodies (FDA Egrifta SV label, 2019).
• Rash, vomiting, indigestion, musculoskeletal stiffness, night sweats, palpitations and raised creatine phosphokinase each occurred in 1 to 3 percent of treated patients, more often than on placebo.

• You are pregnant or trying to conceive. The approved label lists pregnancy as an outright contraindication, not a caution.
• You are breastfeeding. The label addresses lactation only to say that mothers with HIV-1 should not breastfeed, and there is no data on the drug in human milk.
• You have an active cancer. This is a contraindication on the label. For a history of treated, stable cancer the label says to start only after weighing benefit against the risk of reactivating it, and to stop at any sign of recurrence.
• You have disruption of the hypothalamic-pituitary axis, including pituitary tumour, pituitary surgery, radiation, head trauma or structural brain lesions. This is also a contraindication: the drug asks a pituitary to do something it may no longer be able to do.
• You are acutely critically ill after open heart surgery, abdominal surgery, major trauma, or in acute respiratory failure. Increased mortality has been reported with pharmacologic growth hormone in that setting and the label says to consider stopping.
• You have diabetes, prediabetes or diabetic retinopathy and are not being monitored. The label requires glucose status before starting, periodic monitoring during treatment, and regular retinal checks in people with diabetes.
• You have a known hypersensitivity to tesamorelin or to the excipients in the approved product, which include mannitol, sucrose, histidine and polysorbate 20.
• You are under 18. The label states that safety and effectiveness in paediatric patients have not been established.
• You are an athlete subject to drug testing. Tesamorelin is prohibited at all times by the World Anti-Doping Agency, and mass-spectrometry methods able to detect it and its metabolites in urine below the 1 ng/mL required performance limit have been published (Memdouh et al., 2021).
• You are not under a physician who can check IGF-1, fasting glucose and HbA1c before and during use. The label instructs prescribers to monitor IGF-1 and to consider stopping on persistent elevation.

• Judging it by the bathroom scale, or expecting a result to survive four weeks off. The manufacturer's own label states it is not indicated for weight loss and describes the effect as weight neutral; it moves deep abdominal fat, not body weight. The approved drug is also taken continuously, and when patients in the 52-week extension were switched to placebo their visceral fat came back (Falutz et al., 2008).
• Treating the cheatsheet vial as the approved product. Egrifta SV is a 2 mg single-dose vial reconstituted with 0.5 mL of sterile water for a 1.4 mg dose, injected immediately, with the remainder discarded. A 10 mg vial in 2 mL of bacteriostatic water is a research-peptide convention, not a tested presentation, and the concentration arithmetic is entirely different.
• Getting the handling wrong at either end of the injection. The label says to reconstitute by rolling the vial gently between your hands for 30 seconds and explicitly not to shake, and to use the solution only if it is clear, colourless and free of particles; it then instructs rotating sites around the abdomen, because a quarter of patients in the trials got injection-site reactions.
• Skipping bloodwork because it is only a peptide. This drug pushes IGF-1 above 2 standard deviation scores in nearly half of users by 26 weeks and roughly triples the odds of crossing into diabetic HbA1c range, and both are things you only find by testing.
• Assuming the FDA approval covers you. It covers adults with HIV and lipodystrophy. Every other use, including the one most people buy it for, is off-label and rests on a much thinner evidence base.