Tesamorelin’s Impact on Muscle Composition in Adults With HIV: Research Insights

In an exploratory secondary analysis of clinical trials conducted by Adrian et al. (2019), investigators examined how the synthetic growth hormone-releasing hormone analogue tesamorelin influences skeletal muscle quality and quantity in adults living with HIV who had significant visceral adiposity. While earlier work had established tesamorelin’s ability to reduce visceral adipose tissue (VAT) in this population, the researchers noted that its effects on muscle composition — specifically muscle density and area — had not been thoroughly characterized prior to this analysis.
According to the methods described by Adrian and colleagues, the analysis included participants drawn from two previously completed randomized, placebo-controlled clinical trials conducted at multiple sites in the United States and Canada. All participants in the tesamorelin arm were restricted to those who had achieved a clinically meaningful reduction in visceral fat (defined as an ≥8% decrease in VAT). Over a 26-week period, participants received daily subcutaneous injections of tesamorelin or placebo. The researchers used computed tomography (CT) scans at the L4–L5 lumbar vertebral level to measure trunk muscle density in Hounsfield units and muscle cross-sectional area in square centimeters for four major muscle groups.
In the results reported by Adrian et al. (2019), tesamorelin treatment was associated with significant increases in muscle tissue density and size compared with placebo among individuals who had responded with a substantial decrease in visceral adiposity. Specifically, the tesamorelin group showed statistically significant increases in density across four trunk muscle groups (with coefficients ranging from 1.56-4.86 Hounsfield units; all p < 0.005), as well as in lean muscle segments of the anterolateral/abdominal and rectus muscles. Significant increases were also observed in total muscle area of the rectus and psoas muscles and in the lean muscle area across all four muscle groups, indicating gains in both quality and quantity of skeletal muscle.
The authors concluded that among people living with HIV who exhibited a clinically significant decrease in visceral adipose tissue on tesamorelin treatment, the peptide was effective in enhancing skeletal muscle density and area beyond changes in fat distribution alone. They noted that further research is needed to determine the long-term implications of these muscle changes for physical function, metabolic health, and quality of life in both HIV-positive and broader populations.

Important Notice
This content is provided for educational and informational purposes only. The research discussed relates exclusively to laboratory and clinical investigation. No claims are made regarding biological activity, therapeutic use, or clinical outcomes beyond those observed in the study. The peptides referenced are not intended for use outside of controlled research settings.

Sources
Adrian S. et al. (2019). The growth hormone releasing hormone analogue, tesamorelin, decreases muscle fat and increases muscle area in adults with HIV. Journal of Frailty and Aging.