Can Ozempic and Similar Drugs Reduce Heart Size?

Popular weight loss medications like Ozempic and Wegovy are generating excitement due to their impressive short-term outcomes, which include improvements in metabolic health, pain alleviation, and enhancements in cognitive function and addiction recovery.

While these initial results are promising, it is crucial to remain cautious, as the long-term side effects are still being uncovered.

Recently, experts have raised concerns that these innovative weight loss drugs, known as glucagon-like peptide-1 (GLP-1) receptor agonists, may lead to significant loss of skeletal muscle along with fat loss. However, sufficient data to confirm this is lacking.

Adding to this discussion, researchers at the University of Alberta have focused on cardiac muscles, which play a vital role in pumping blood throughout the body. Surprisingly, little research has been done on how these tissues respond to GLP-1 agonists.

In their study, the team administered semaglutide—the active ingredient in Ozempic—to both lean and obese mice for 21 days. They observed that the obese mice lost about 30% of their body weight, while lean mice experienced an approximate 8% reduction in skeletal muscle.

Although heart function and wall thickness remained unchanged, both groups exhibited reductions in overall heart mass and the size of individual heart muscle cells. The authors concluded that these changes appeared to occur independently of weight loss, raising questions about the long-term implications.

They urged that cardiac structure and function should be diligently assessed in clinical studies of these medications, especially considering the large number of patients who may continue using them in the future.

The study was published in The Lancet.