Tesamorelin

Definition

Tesamorelin is a synthetic analogue of growth hormone-releasing hormone, the hypothalamic peptide that signals the pituitary gland to release growth hormone. The molecule carries the full 44-amino-acid GHRH sequence with a trans-3-hexenoyl group at its amino terminus; the modification slows enzymatic degradation and extends activity after subcutaneous injection ^[1].

Stimulating the pituitary rather than replacing growth hormone directly preserves the body's own feedback control. Growth hormone and insulin-like growth factor 1 rise within a physiological pattern, which distinguishes GHRH analogues from injected growth hormone itself.

Evidence

The approval rests on randomized, placebo-controlled phase 3 trials in HIV-infected adults with excess visceral fat. In the trial reported by Falutz and colleagues, 404 patients received tesamorelin 2 mg or placebo daily by subcutaneous injection; visceral adipose tissue fell 10.9 percent in the treatment group against 0.6 percent with placebo over six months, and the reduction reached approximately 18 percent in patients who continued through a full year ^[1]. A pooled analysis of the two phase 3 studies and a long-term safety report are published separately ^{[2, 3]}.

Use outside the approved indication is not supported by registrational evidence. The trials enrolled HIV-infected patients with lipodystrophy; no phase 3 data exist for cosmetic fat reduction, athletic performance, or longevity applications.

A small controlled literature does exist outside that population, and it does not test the claim the marketplace makes for the molecule. A twelve-month randomized trial in 60 abdominally obese adults without HIV, selected for reduced growth hormone secretion, found visceral adipose tissue fell 35 square centimeters against placebo, with a 95 percent confidence interval of −58 to −12 and p equal to 0.003; abdominal subcutaneous fat did not change significantly, at p equal to 0.40 ^[5]. A twelve-week randomized trial in 53 patients with type 2 diabetes was a safety study, and found no change in insulin response or glycemic control ^[6]; a twenty-week randomized trial in 152 older adults measured cognition rather than body composition ^[7].

Counted across every name the compound is indexed under, the whole controlled record is 26 papers carrying the randomized-controlled-trial publication type, 20 of which name HIV or lipodystrophy ^[8]. The literature is a narrow one, and it is narrow in a particular direction: every population enrolled in it was selected for a deficit.

Side effects

The EGRIFTA WR and EGRIFTA SV labels list the same most common adverse reactions, each reported in more than 5 percent of treated patients: arthralgia, injection site erythema, injection site pruritus, pain in an extremity, peripheral edema and myalgia ^{[9, 10]}. Injection site reactions, including redness, itching, pain, irritation and bruising, occurred in 25 percent of treated patients against 14 percent with placebo during the first 26 weeks of the trials ^[9].

The label's warnings follow from raising growth hormone. Fluid retention can appear as edema, joint pain or carpal tunnel syndrome, and is either transient or resolves when treatment stops. Glucose intolerance can develop: in the trials, 5 percent of treated patients against 1 percent on placebo reached an HbA1c of 6.5 percent or higher ^[9]. IGF-1 rises, the effects of prolonged elevation are unknown, and the label calls for monitoring it. Hypersensitivity reactions, including rash, itching, flushing and hives, occurred in 4 percent of treated patients ^[9].

The label also warns of an increased risk of neoplasms, since growth hormone is a growth factor, and advises considering discontinuation in acute critical illness ^[9]. Tesamorelin side effects sets out the full adverse-reaction table and what the trials measured before and after treatment. Tesamorelin is contraindicated in pregnancy, in active malignancy, in known hypersensitivity to tesamorelin or its excipients, and in disruption of the hypothalamic-pituitary axis from hypophysectomy, hypopituitarism, pituitary tumor or surgery, head irradiation or head trauma ^[9].

Educational summary of the cited sources, not medical advice; a prescriber weighs these risks against a person’s own history.

Lawful access

Tesamorelin has been an approved drug in the United States since November 2010, first marketed as EGRIFTA. In March 2025 the FDA approved EGRIFTA WR, a more concentrated formulation reconstituted weekly rather than daily, which replaces the earlier EGRIFTA SV presentation ^[4]. It remains the only medication approved in the United States for the reduction of excess abdominal fat in adults with HIV who have lipodystrophy.

Both prescribing labels were still listed on DailyMed in September 2026, and the EGRIFTA WR label states that the two formulations are not substitutable ^{[9, 10]}. Drugs@FDA records the original approval on November 10, 2010 and the EGRIFTA WR supplement on March 25, 2025, both under the same application ^[11].

The approved product is the only lawful supply route, and the reason is the molecule's size. Tesamorelin carries the 44-amino-acid sequence of human GHRH ^[9], and the FDA rule defining a biological product treats any amino acid polymer with a specific, defined sequence of more than 40 amino acids as a protein ^[14]. On March 23, 2020 the EGRIFTA application was deemed a biologics license, BLA 022505 ^{[11, 12]}, and from that date biological products that made the transition are not eligible for the compounding exemptions in sections 503A and 503B ^[13]. Compounded tesamorelin has no lawful route under either section.

Related molecules

Tesamorelin is the approved drug of the GH secretagogues class, beside sermorelin, which is compounded under 503A, and CJC-1295, which has no lawful route; the molecule index records each posture. Sermorelin vs tesamorelin compares the two GHRH analogs on structure, evidence and legal access. A contrasting case is BPC-157, a peptide with wide commercial visibility, no approved product, and no completed human trial. Secretin is the opposite contrast: an approval held since 2004 alongside a bulk nomination the agency filed as inadequately supported.

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