In obese male mice, combining semaglutide with a treatment that blocks GDF8 and activin A leads to about twice as much fat loss over four weeks compared to semaglutide alone, even when total weight loss is the same, indicating that preserving muscle may help the body remove more fat.

In obese male primates, combining a drug that blocks two specific muscle-regulating proteins with semaglutide leads to greater increases in muscle mass and more fat loss than semaglutide alone, along with improved blood sugar and cholesterol levels after 20 weeks of treatment.

In obese male mice and non-human primates, blocking two specific proteins (GDF8 and activin A) while using a GLP-1 receptor agonist helps maintain or increase muscle mass and enhances fat loss, leading to better body composition and improved metabolic indicators like lower liver fat and healthier blood lipids.

If you're an adult with extra weight but don't have diabetes, taking a weekly 2.4 mg shot of semaglutide for about a year and a half can help you lose around 13 kg of fat, including some deep belly fat, while mostly keeping your muscle — even though you might lose a little muscle too, the fat loss is much bigger.

People with obesity and another health issue who got a weekly shot of semaglutide plus behavioral therapy lost about 17 kg on average after a year and a half — way more than those who got a placebo.

When adults with obesity take a drug called semaglutide 2.4 mg for about 1.5 years, nearly 9 out of 10 lose at least 5% of their body weight — compared to only about 1 in 3 to half of those taking a sugar pill or another drug, meaning semaglutide works better for weight loss in most people.