Tesamorelin: A Stabilized GHRH Analogue in Growth Hormone and Metabolic Research
Research Use Only. This article is for scientific and educational reference only. All products are sold for research purposes and are not intended for human or animal consumption.
Overview
Tesamorelin (CAS 218949-48-5) is a 44-amino acid synthetic peptide analogue of endogenous growth hormone-releasing hormone (GHRH), modified by the addition of a trans-3-hexenoic acid group at the N-terminus. This modification confers greater stability against dipeptidyl peptidase IV (DPP-IV) degradation compared to native GHRH, extending the peptide's biological activity while preserving its receptor binding affinity.
The peptide acts on the pituitary gland to stimulate the pulsatile release of endogenous growth hormone (GH), maintaining the physiological pattern of GH secretion rather than delivering exogenous GH directly. This distinction is considered important in research contexts where preservation of the GH axis feedback mechanism is a study parameter. Tesamorelin has a molecular weight of approximately 5,135 Da.
Mechanism of Action
Tesamorelin binds to GHRH receptors on somatotroph cells in the anterior pituitary gland, stimulating the synthesis and pulsatile release of growth hormone. The resulting increase in circulating GH subsequently stimulates hepatic production of insulin-like growth factor 1 (IGF-1), which mediates many of the downstream anabolic and metabolic effects attributed to the GH/IGF-1 axis.
Unlike exogenous recombinant human growth hormone (rhGH), tesamorelin preserves the negative feedback loop of the hypothalamic-pituitary axis. Somatostatin-mediated inhibition remains intact, which researchers have proposed may reduce the risk of GH excess and associated adverse effects. The trans-3-hexenoic acid modification at the N-terminus protects the peptide from rapid cleavage by DPP-IV, extending its plasma half-life compared to native GHRH(1-44).
Key Research Findings
The most extensively studied application of tesamorelin is in HIV-associated lipodystrophy, a condition characterized by excess visceral adipose tissue accumulation associated with antiretroviral therapy. Two pivotal Phase 3 trials (LIPO-010 and LIPO-011) demonstrated that tesamorelin 2 mg/day subcutaneously produced statistically significant reductions in visceral adipose tissue (VAT) as measured by CT scan, with mean reductions of approximately 15–18% from baseline over 26 weeks compared to placebo.
Research has also examined tesamorelin's effects in non-HIV populations, including adults with abdominal obesity and age-related GH deficiency. Studies have reported improvements in body composition (reduced fat mass, preserved lean mass), lipid profiles (reduced triglycerides), and physical function parameters. Cognitive research in older adults has explored potential effects on memory and executive function, hypothesizing that GH/IGF-1 axis stimulation may support neurological health.
Chemical Properties
| Property | Value | |---|---| | Molecular Formula | C₂₂₁H₃₆₆N₇₂O₆₇S₁ | | Molecular Weight | ~5,135 Da | | CAS Number | 218949-48-5 | | Form | Lyophilized powder | | Purity (research grade) | ≥99% HPLC | | Storage | −20°C, protect from light |
Research Considerations
Tesamorelin is supplied as a lyophilized powder requiring reconstitution with sterile water or bacteriostatic water. Research protocols should account for the pulsatile nature of GH release when designing sampling schedules for GH or IGF-1 measurements. The peptide's activity is dependent on intact pituitary function; research in models with pituitary insufficiency will require different experimental design considerations.
Research Use Only. This article is for scientific and educational reference. All products are sold for research purposes only and are not intended for human or animal consumption.