Tesamorelin is a synthetic analogue of growth hormone–releasing factor (GRF/GHRH). It stimulates the pituitary gland to release endogenous growth hormone, which subsequently increases IGF-1 and related growth factors. Unlike direct administration of growth hormone, tesamorelin works by activating the body's own GRF receptors. Its established U.S. indication is reduction of excess abdominal fat in HIV-infected adults with lipodystrophy; it is not indicated as a general weight-loss drug.
Key Points
Drug class: Growth hormone–releasing factor analogue
Primary mechanism: Stimulates GRF receptors on pituitary somatotroph cells.
Hormonal effects: Increases endogenous growth hormone secretion and subsequently raises IGF-1 and IGFBP-3 levels.
Approved indication: Reduction of excess abdominal fat in HIV-infected adults with lipodystrophy.
Weight loss: Not indicated for general weight management; the prescribing information describes a weight-neutral effect.
Administration: Subcutaneous injection.
Common adverse effects: Injection-site reactions, joint pain, muscle pain, peripheral edema, and increased IGF-1 may occur.
Important risks: Elevated IGF-1, fluid retention, glucose intolerance, and hypersensitivity reactions require consideration.
Regulatory status: FDA-approved for its specific indication, with the current products including EGRIFTA SV and EGRIFTA WR.
Specifications
Generic name: Tesamorelin
Salt form: Tesamorelin acetate
Chemical class: Synthetic peptide/GRF analogue
Peptide length: 44 amino acids derived from human GRF, modified with an N-terminal hexenoyl group.
Molecular weight: Approximately 5,135.9 Da as free-base equivalent.
Route: Subcutaneous
Form: Lyophilized powder requiring reconstitution
EGRIFTA SV: 2 mg tesamorelin per vial; after reconstitution, 2 mg/0.5 mL.
EGRIFTA WR: 11.6 mg tesamorelin per vial; after reconstitution, 8 mg/mL.
Initial U.S. approval: 2010
Approved indication: HIV-associated lipodystrophy with excess abdominal fat.
Important: Tesamorelin should be used only for its approved indication and under medical supervision. It is not equivalent to recombinant growth hormone and should not be used simply as a general bodybuilding or weight-loss agent.
