Popular weight loss drugs boost natural killer (NK) cells, which may improve their ability to combat cancer. Glucagon-like peptide-1 (GLP-1) analogs, such as semaglutide (Ozempic and Wegovy), originally developed for diabetes, are also used to treat obesity, which is linked to at least 13 types of cancer. Losing weight can help reduce cancer risk, but GLP-1 analogs may have a more direct effect.

Twenty study participants with obesity and defective NK cell function received semaglutide once weekly for six months. While the number of circulating NK cells did not change, their function improved. In laboratory experiments, NK cells from treated patients were better able to kill cancer. Even people who didn’t lose weight saw a benefit.

“The current findings represent very positive news for people living with obesity on GLP-1 therapy and suggest the benefits of this family of treatments may extend to a reduction in cancer risk,” said Donal O’Shea, MD, of University College Dublin.