Clinical Uses of Tesamorelin: What the Trials Show

What tesamorelin is approved for

Most peptides on this site have animal data, a few small human studies and a lot of forum reports. Tesamorelin is a prescription drug, first approved in the US in 2010 as Egrifta on the strength of two 26-week Phase 3 trials. The approval is narrow. The label covers "the reduction of excess abdominal fat in HIV-infected adult patients with lipodystrophy" and says the drug is not indicated for weight loss "as it has a weight neutral effect."

As of October 2026, the current US product is Egrifta WR, approved on March 25, 2025. It's mixed once a week instead of daily, and the manufacturer says it will replace Egrifta SV. The approved use didn't change.

Lifters pay attention because tesamorelin lowers visceral fat, the fat stored around the organs, through the body's own growth hormone (GH) system. Whether that carries over to lean, healthy people is a question no trial has answered. For other compounds studied for fat loss, including prescription GLP-1 medicines, see our overview of fat-loss peptides.

How It Coaxes Your Pituitary (and Why It Matters)

Tesamorelin is a GHRH analog, a synthetic version of the hormone the hypothalamus uses to signal GH release. Per the label, it's the 44-amino-acid sequence of human GHRH plus a short hexenoyl chain, and in lab tests it binds the GHRH receptor about as strongly as the natural hormone.

GH peptides work through one of two receptors. Tesamorelin, sermorelin, Mod GRF 1-29 and CJC-1295 act on the GHRH receptor. GHRP-2, GHRP-6 and ipamorelin are secretagogues that mimic ghrelin and act on the ghrelin receptor (GHSR).

Tesamorelin uses only the GHRH route. The label reports no clinically significant changes in ACTH (which drives cortisol) or prolactin in the trials. For contrast, a 1998 study in pigs found that GHRP-2 and GHRP-6 raised ACTH and cortisol, while ipamorelin did not. Users also describe strong hunger on GHRP-6, which fits its ghrelin-like action.

The pituitary still releases GH in pulses, and the main downstream signal is insulin-like growth factor 1 (IGF-1). The label lists a half-life of about 11 minutes for Egrifta WR in healthy adults. Our page on how CJC-1295 and ipamorelin work together covers how users combine the two receptor routes.

The Hard Numbers: What the FDA Saw

The two Phase 3 trials were double-blind and placebo-controlled, with 816 adults with HIV and excess abdominal fat. Participants injected 2 mg of the original Egrifta or a placebo once daily for 26 weeks, and visceral fat was measured by CT scan.

• Visceral fat: down 18% vs up 2% on placebo in Study 1, and down 14% vs down 2% in Study 2 (label figures). The first trial's 2007 report in the New England Journal of Medicine gave -15.2% vs +5.0%.
• Belly fat under the skin: no meaningful change in a pooled analysis of both trials.
• Body weight: essentially unchanged. Lean body mass rose about 1.2-1.3 kg vs almost no change on placebo.
• Blood markers: in the 2007 trial, IGF-1 rose 81% and triglycerides fell 50 mg/dL (vs up 9 mg/dL on placebo).

The effect lasts only as long as treatment does. People who stayed on tesamorelin through week 52 kept their visceral fat reduction. Those switched to placebo at week 26 regained about 1.1-1.4 kg of trunk fat and lost about 1.7-1.8 kg of lean mass, according to the label, and a 2011 review in Drugs notes that visceral fat came back after stopping.

Waist circumference fell 1-2 cm more than on placebo. Keep in mind who was studied: adults with HIV-associated fat gain and an average BMI of about 29, not lean athletes.

Other clinical uses studied

As of October 2026, none of these uses is approved.

• Liver fat in HIV. In a 2014 JAMA trial of 50 adults with HIV and abdominal fat, 6 months of 2 mg daily modestly reduced liver fat compared with placebo. A 2019 Lancet HIV trial enrolled 61 people with HIV and fatty liver disease. After 12 months, liver fat fell by a relative 37% vs placebo, and 35% of the tesamorelin group vs 4% on placebo dropped below the 5% liver-fat threshold that defines the condition.
• Cognition in older adults. A 2012 trial gave 152 adults aged 55-87, 66 of them with mild cognitive impairment, 1 mg daily or a placebo for 20 weeks. The tesamorelin group scored better on cognitive tests, mainly executive function. Mild adverse events were also more common (68% vs 36%).

These are small trials from a few academic groups, so they're leads rather than settled findings.

From Clinic to Gym: Comparing Your Options

Only tesamorelin has outcome trials behind it, and only in one patient group.

Community guides often say CJC-1295 with DAC gives low, steady GH, a "GH bleed." The one human study that measured overnight GH patterns found otherwise. In 2006, healthy men aged 20-40 got a single 60 or 90 mcg/kg injection. A week later their GH pulses kept the same frequency and size, while trough GH was about 7.5 times higher and mean GH was up 46%. The pulses stayed; the baseline rose underneath them.

Many users pair Mod GRF 1-29 with ipamorelin to act on both receptors at once. The reasoning is plausible, but we found no controlled human trial of that combination, and no trial has compared any of these peptides head-to-head with tesamorelin.

Protocols, Dosing, and What to Expect

Reported doses differ by source:

• Phase 3 trials: 2 mg of the original Egrifta once daily by subcutaneous injection into the abdomen, in adults with HIV lipodystrophy.
• Egrifta WR label (2025): 1.28 mg once daily, which gives exposure similar to the original 2 mg dose. The label says the formulations are not substitutable, so milligram amounts don't transfer between products.
• Cognition trial (2012): 1 mg daily, self-injected about 30 minutes before bedtime, in older adults.
• User reports: users on peptide forums commonly describe 1-2 mg nightly, often 5 days on and 2 off. Some have dropped to about 1.3 mg, citing the WR label.

The label sets no time of day and no fasting rule. Advice to inject before bed, or on an empty stomach about 2 hours after a meal, comes from vendor and community guides. Community runs are usually shorter than the 26-52 weeks studied, sometimes with planned breaks; we found no study of on/off cycling with tesamorelin.

The trials measured their main outcome at 26 weeks; the label notes IGF-1 above the normal range as early as week 13. Egrifta WR is a lyophilized powder mixed with bacteriostatic water. Research-market vials are a different product, and no regulator checks their content.

The Price of Admission: Risks and Reality

Side effects reported in the label and trials:

• Injection-site reactions such as redness, itching and bruising: 25% vs 14% on placebo over 26 weeks.
• Fluid retention, showing up as swelling, joint pain or carpal tunnel syndrome. The label says these pass or resolve after stopping.
• Blood sugar: HbA1c reached 6.5% or higher in 5% vs 1% on placebo, and the label advises checking glucose before and during treatment.
• High IGF-1: after 26 weeks, 47% of patients had IGF-1 more than 2 standard deviations above normal. The label says the effects of long-term elevation are unknown.
• Allergic reactions such as rash or hives, in 4% of trial patients.

The label rules out use in active cancer, in pregnancy, and after disruption of the hypothalamic-pituitary axis such as pituitary surgery. Long-term cardiovascular safety hasn't been established.

Users on peptide forums describe water retention around weeks 3-4, tingling hands, IGF-1 well above the lab range, and higher fasting glucose. Those reports match the label's warnings, though users usually aren't monitored the way trial participants were. Our page on monitoring and contraindications covers the lab markers people commonly track.

Legal and sport status as of October 2026

Egrifta is a prescription medicine in the US. In FDA's view, tesamorelin sold as a "research" product isn't in a gray area. In an August 24, 2026 warning letter, FDA called a research-peptide vendor's tesamorelin an unapproved new drug, despite "research use only" and "not for human consumption" labels. It cited the product descriptions and the sale of bacteriostatic water as evidence of intended human use. Our guide to what "research only" means legally has more detail.

WADA's 2026 Prohibited List names tesamorelin among GHRH analogues (S2.2.4), banned at all times for tested athletes. See peptide rules in competitive sport for how testing works.

What we still don't know

• Whether the visceral fat effect seen in HIV-associated fat gain applies to healthy, lean people.
• Long-term cardiovascular safety and the effects of years of raised IGF-1.
• Whether 5-on, 2-off schedules work as well as the daily dosing used in trials.
• How research-market tesamorelin compares with the approved product in content and purity.