Tesamorelin increased rectus lean muscle by 0.85 cm² in people with HIV and belly fat, and this effect stayed strong even after considering belly fat loss.

Tesamorelin increased rectus and psoas muscle size by 0.44 and 0.46 cm² in people with HIV and belly fat, and this effect remained even after accounting for belly fat loss.

HIV patients with belly fat who responded to tesamorelin had bigger rectus and psoas muscles (0.44 and 0.46 cm² larger) compared to placebo after 26 weeks.

People with HIV and belly fat who responded to tesamorelin by losing belly fat saw their trunk muscles grow larger in specific areas: rectus abdominis by 0.85 cm², psoas by 0.64 cm², and others by up to 1.08 cm² more than those on placebo after 26 weeks.

The drug made the lean parts of the abdominal and rectus muscles denser—meaning they had less fat inside them—more than other muscles, showing it targeted key core muscles.

Tesamorelin increased rectus and psoas muscle size by 0.44 and 0.46 cm² in people with HIV and belly fat, but this effect was reduced when considering changes in a growth hormone-related factor.