Description

Tesamorelin

Tesamorelin is a synthetic analogue of human growth hormone-releasing hormone (GHRH) consisting of the full 44-amino acid sequence of endogenous GHRH(1-44)-NH2 conjugated to a trans-3-hexenoic acid moiety at the N-terminus. This modification confers improved plasma stability and resistance to dipeptidyl peptidase IV (DPP-IV) degradation relative to native GHRH, extending its bioactive half-life in experimental systems. Molecular formula: C223H370N72O69S; molar mass: 5,195.91 g/mol; CAS No. 901758-09-6; PubChem CID: 44147413. It is provided as a lyophilized powder of greater than 99% purity for reconstitution in aqueous research buffers.

Mechanism of Action

Tesamorelin binds with high affinity to the growth hormone-releasing hormone receptor (GHRHR), a Gs-protein-coupled receptor expressed on anterior pituitary somatotroph cells. Receptor activation stimulates adenylyl cyclase, elevating intracellular cyclic AMP (cAMP) concentrations, which triggers the release of pre-formed growth hormone (GH) granules and induces new GH synthesis. The resulting physiological GH pulse stimulates hepatic production of insulin-like growth factor-1 (IGF-1), the principal downstream mediator of GH’s metabolic and anabolic effects in peripheral tissues.

Unlike exogenous recombinant GH administration, which produces pharmacological supraphysiological GH levels, tesamorelin stimulates endogenous pituitary GH secretion within a physiological pulsatile framework. Endogenous negative feedback mechanisms (somatostatin release in response to elevated GH) remain functionally intact, providing a more controlled GH elevation profile in preclinical models. This characteristic has made tesamorelin a widely used tool for studying GHRH receptor pharmacology and GH axis dynamics.

Observed Effects in Preclinical and Clinical Research

In animal models, tesamorelin administration produces dose-dependent increases in plasma GH and IGF-1, with downstream effects on lipid metabolism including reduced visceral adiposity and improved lipid profiles. In clinical investigations, tesamorelin (approved by the FDA in 2010 under the trade name Egrifta for HIV-associated lipodystrophy) demonstrated statistically significant reductions in visceral adipose tissue (VAT) measured by CT scan, alongside improvements in triglyceride levels and waist circumference in treated populations. These clinical outcomes provide validation for using tesamorelin as a reference compound in preclinical models of GH axis-mediated visceral fat regulation and lipid metabolism.

Preclinical models have also investigated tesamorelin in the context of age-related somatotropic decline, demonstrating partial restoration of GH pulsatility and IGF-1 levels in aged rodent cohorts. Studies of cognitive function in animal models have explored potential associations between tesamorelin-induced IGF-1 elevations and hippocampal neurogenesis and synaptic plasticity markers, an area of active preclinical investigation.

Research Applications

Tesamorelin is investigated as a research tool in preclinical models of GH axis stimulation and GHRHR pharmacology, visceral adiposity and lipid metabolism under GH modulation, age-related somatotropic axis decline, body composition studies involving IGF-1-mediated effects on lean and adipose tissue, lipodystrophy models, and cognitive function studies linked to GH/IGF-1 signaling.

Peptide Characteristics

Certificate of Analysis

• Purity COA – Tesamorelin 5mg
• Endotoxin COA – Tesamorelin 5mg

FOR RESEARCH USE ONLY. NOT FOR HUMAN USE. NOT INTENDED FOR DIAGNOSIS, TREATMENT, OR PREVENTION OF ANY CONDITION.