Tesamorelin and Skeletal Muscle Composition: Evidence From Clinical Research

In a secondary exploratory analysis of previously completed clinical trials, researchers led by Adrian et al. (2019) investigated whether the synthetic growth hormone-releasing hormone analogue tesamorelin affects skeletal muscle quality and quantity in adults living with HIV who also have abdominal obesity. Tesamorelin has been studied for its ability to reduce visceral adipose tissue in people with HIV-associated lipodystrophy, but its impact on muscle characteristics had not been thoroughly examined before this work.
According to the methods described by Adrian and colleagues, the analysis included participants from two randomized (2:1) clinical trials conducted at sites in the United States and Canada. All participants had abdominal obesity and people assigned to tesamorelin were limited to those who met a response criterion of at least an 8% decrease in visceral adipose tissue. The peptide was compared with placebo over a 26-week period. Quantitative computed tomography (CT) scans at the L4–L5 lumbar vertebral level were used to measure muscle density and area (in Hounsfield units and square centimeters, respectively) of four trunk muscle groups, including lean muscle segments, with adjustments made for baseline values and treatment arm in statistical models.
The results reported by Adrian et al. (2019) showed that participants who responded to tesamorelin treatment experienced significant increases in both muscle density and muscle area across multiple trunk muscle groups compared with placebo. Specifically, tesamorelin was associated with greater increases in muscle density (coefficients ranging from 1.56 to 4.86 Hounsfield units; all p < 0.005) and lean muscle density of the anterolateral/abdominal and rectus muscles (1.39 and 1.78 Hounsfield units; both p < 0.005). The peptide also produced significant gains in total muscle area for muscles such as the rectus and psoas (0.44 and 0.46 cm²; p < 0.005) as well as in the lean area of all four trunk muscle groups analyzed (0.64–1.08 cm²; p < 0.005).
In their conclusions, the authors noted that among adults living with HIV who demonstrated a clinically meaningful reduction in visceral adipose tissue, tesamorelin treatment was effective in increasing skeletal muscle area and density beyond changes in fat alone. They also suggested that further research is warranted to understand the long-term implications of these muscle changes for people both with and without HIV, and to clarify how such changes might affect daily function and health outcomes.

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 outcomes beyond what was observed in the study. Peptides referenced are not intended for human or veterinary use outside of controlled research contexts.

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