Tesamorelin

This 26-week multicenter, double-blind, placebo-controlled Phase 3 study randomized 412 adults with HIV-associated abdominal fat accumulation to a daily 2 mg subcutaneous dose of tesamorelin or placebo. The primary endpoint was percent change in visceral adipose tissue (VAT) measured by computed tomography. Tesamorelin produced a mean VAT reduction of approximately 15.2% from baseline, compared with a 5% increase in the placebo arm (between-group difference p<0.001). Triglycerides and the cholesterol-to-HDL ratio improved in the tesamorelin arm, and IGF-1 rose into the upper-normal physiologic range consistent with pulsatile pituitary GH release rather than exogenous GH administration. Glucose parameters and adverse event rates were broadly similar between arms over the 26-week window. The authors concluded that tesamorelin selectively reduced visceral adiposity through stimulation of endogenous GH secretion.

This was the large landmark trial that established what tesamorelin does in humans. Roughly 400 people received either tesamorelin or a placebo injection daily for six months, and researchers measured belly fat with CT scans. The tesamorelin group lost about 15% of their visceral (deep abdominal) fat, while the placebo group gained a little. Importantly, tesamorelin worked by telling the body's own pituitary gland to release growth hormone in its natural rhythm, rather than by adding outside growth hormone.

This 6-month, double-blind, randomized clinical trial enrolled 50 HIV-positive participants with abdominal fat accumulation and assigned them to tesamorelin 2 mg subcutaneously daily or placebo, with the primary endpoint being change in hepatic fat fraction measured by proton magnetic resonance spectroscopy (1H-MRS). Tesamorelin produced a significant absolute reduction in hepatic fat fraction relative to placebo (between-group effect approximately -2.9%, p=0.003), corresponding to a roughly 37% relative reduction in liver fat. Visceral adipose tissue also decreased significantly versus placebo, and IGF-1 rose within the physiologic range. Fasting glucose and HbA1c were unchanged between arms across the trial. The authors interpreted the data as evidence that GHRH-axis stimulation can favorably alter ectopic fat distribution in the liver, not only the visceral depot.

This study asked whether tesamorelin affects fat stored inside the liver, not just belly fat. Fifty participants received daily tesamorelin or placebo for six months, and researchers used a specialized MRI to measure how much fat was sitting inside their liver tissue. The tesamorelin group saw their liver fat drop by about a third compared with placebo. This was important because excess liver fat is linked to a range of metabolic conditions, and the finding suggested the GHRH pathway can influence where the body stores fat at a deeper level than was previously documented.