How Tesamorelin Works: NUPEPS Scientific Overview
1. Activation of the GH–IGF-1 Axis
Tesamorelin binds to GHRH receptors in the anterior pituitary, activating downstream signaling pathways such as JAK-STAT to enhance GH release. Circulating GH then stimulates hepatic production of insulin-like growth factor-1 (IGF-1), a key mediator of fat metabolism.
IGF-1 contributes to healthier lipid regulation by:
- Supporting adipocyte function
- Promoting fatty acid uptake and oxidation
- Reducing intracellular fat accumulation
Because the GH–IGF-1 axis is often impaired in HIV due to disease progression and ART exposure, Tesamorelin can help restore more normal metabolic activity.
2. Direct Impact on Adipocyte Metabolism
Promoting Lipolysis
Tesamorelin enhances the activity of hormone-sensitive lipase (HSL), a key enzyme responsible for breaking down triglycerides into glycerol and fatty acids. By engaging cAMP–PKA signaling, Tesamorelin further increases lipolytic activity, supporting reductions in adipocyte fat storage—especially in VAT.
Enhancing Fatty Acid Oxidation
Tesamorelin increases the activity of carnitine palmitoyltransferase-1 (CPT1), the rate-limiting enzyme for mitochondrial fatty acid β-oxidation. It also upregulates other oxidative enzymes such as ACC2 and FATP1, promoting more efficient fatty acid breakdown and supporting metabolic balance.
3. Regulation of Lipid Metabolism–Related Gene Expression
Influence on Adipogenesis
Tesamorelin can suppress expression of key adipogenic transcription factors such as:
- PPARγ
- C/EBPα
By inhibiting adipocyte differentiation pathways and reducing expression of associated genes (e.g., FABP4, FAS), Tesamorelin helps limit excessive fat production.
Regulation of Lipid Transport Genes
Tesamorelin has been shown to:
- Reduce ApoB expression, which may lower levels of VLDL and LDL
- Increase ApoA-I expression, supporting healthier HDL function and potentially assisting cholesterol transport
These regulatory effects contribute to improved lipid profiles in individuals with HIV-related metabolic disturbances.
Clinical Effects of Tesamorelin in HIV-Related Fat Metabolism
1. Reduction of Visceral Adipose Tissue (VAT)
Clinical studies—including Phase III trials—have demonstrated that Tesamorelin significantly reduces VAT in people with HIV, regardless of baseline characteristics such as dorsocervical fat pads. Reductions in VAT may also correlate with decreases in metabolic risk factors.
2. Improvements in Liver Fat and NAFLD-Related Biomarkers
In HIV-positive individuals with NAFLD, Tesamorelin produced:
- Significant reductions in hepatic fat fraction (HFF)
- A higher percentage of participants achieving HFF below 5%
Gene expression and proteomic analyses suggest Tesamorelin may beneficially modulate pathways linked to inflammation and fibrosis, with reductions observed in proteins such as VEGFA, TGFB1, and CSF1.
3. Effects on Whole-Body Fat Distribution
Tesamorelin has been associated with:
- Decreased trunk fat
- Improved waist circumference
- Better overall body composition without increasing BMI
These improvements reflect healthier fat distribution rather than changes in total body weight.
Intended Use and Target Population
Tesamorelin is designed for adults living with HIV who exhibit abnormal fat accumulation—particularly elevated visceral fat—often verified using imaging such as CT or MRI. These individuals may also present with metabolic indicators such as increased waist circumference or dysregulated lipid profiles.
Conclusion
NUPEPS Peptides recognizes Tesamorelin as a significant scientific advancement for addressing HIV-related fat metabolism abnormalities. Through its multi-pathway biological actions—including activation of the GH–IGF-1 axis, enhancement of adipocyte metabolism, and regulation of lipid-related gene networks—Tesamorelin supports reductions in visceral fat, improvements in liver fat dynamics, and healthier body composition.