Tesamorelin
Tesamorelin
Tesamorelin is a synthetic peptide mimicking human growth hormone-releasing hormone (GHRH), designed to potently and selectively stimulate growth hormone (GH) secretion. Its 44-amino acid structure includes an N-terminal trans-3-hexenoyl group, enhancing its binding affinity to the GHRH receptor on pituitary somatotroph cells.
Upon binding, Tesamorelin induces a conformational change in the GHRH receptor, activating the associated G-protein (Gs). This triggers adenylate cyclase to convert ATP into cyclic AMP (cAMP), which activates protein kinase A (PKA). PKA phosphorylates transcription factors, notably CREB (cAMP response element-binding protein), which binds to GH gene promoter regions, boosting transcription. This leads to the production of prepro-GH, processed into mature GH and stored in secretory vesicles.
Tesamorelin mimics the natural pulsatile release of GHRH, preserving physiological GH peaks essential for metabolic functions like lipolysis and fatty acid oxidation. Its targeted action on visceral adipose tissue is particularly significant, as GH upregulates lipolytic enzymes (e.g., hormone-sensitive lipase) and inhibits lipogenesis, reducing visceral fat—a key therapeutic outcome for HIV-associated lipodystrophy. This effect is mediated by GH-driven pathways involving STAT5b and the insulin-like growth factor 1 (IGF-1) axis, which also supports metabolic health in liver and muscle tissues.
By offering high receptor specificity, potent GH stimulation, and a favorable safety profile, Tesamorelin is an advanced therapeutic for managing GH deficiency and excess abdominal fat.