Tesamorelin

Tesamorelin is a stabilized GHRH analog that boosts GH and IGF-1 secretion, reduces visceral fat, and improves lipid metabolism. FDA-approved for HIV lipodystrophy; studied for cognition and nerve repair.

- Reduce visceral fat and improve GH-related metabolism

- Support cognitive or nerve health

Mechanism of Action

How this peptide works in the body

GHRH Receptor Binding:

Tesamorelin binds to growth hormone-releasing hormone receptors (GHRHR) in the anterior pituitary, activating G-protein-coupled receptor (GPCR) signaling. This stimulates adenylate cyclase, increasing cyclic adenosine monophosphate (cAMP) levels, which in turn activates protein kinase A (PKA).

GH Synthesis and Release:

PKA phosphorylates cAMP response element-binding protein (CREB), enhancing GH1 gene transcription and growth hormone (GH) synthesis. GH is then secreted in a pulsatile manner, maintaining physiological rhythm and avoiding receptor desensitization.

IGF-1 Production:

GH binds to growth hormone receptors (GHR) in the liver, activating JAK2/STAT5 signaling, which induces insulin-like growth factor-1 (IGF-1) synthesis. IGF-1 mediates anabolic effects, promoting muscle growth, tissue repair, and neuroprotection while also enhancing lipid and glucose metabolism.

Lipolysis and Metabolism:

IGF-1 upregulates hormone-sensitive lipase (HSL) and adipose triglyceride lipase (ATGL), increasing lipolysis in visceral fat and reducing adipocyte differentiation. Additionally, GH promotes hepatic gluconeogenesis and increases fatty acid oxidation, optimizing energy metabolism.

Feedback Regulation:

Tesamorelin maintains the hypothalamic-pituitary feedback loop, allowing somatostatin (growth hormone-inhibiting hormone, GHIH) to modulate excessive GH release. This prevents overstimulation and reduces the risk of GH-related side effects seen with direct GH administration.