Swedish Oral Drug Boosts Muscle Metabolism to Burn Fat Without Muscle Loss, Early Study Finds

Researchers in Sweden have reported an experimental oral medication—referred to as compound 15—that appears to increase muscle metabolism, promote fat oxidation and help control blood glucose without causing muscle loss. The work offers a different approach to weight and blood-sugar management than injectable GLP-1 drugs such as semaglutide (Ozempic), which primarily act by suppressing appetite.

While injectable GLP-1s work by suppressing appetite, this new treatment boosts metabolism in the muscles.

Study Design and Main Findings

The study, led by teams at Karolinska Institutet and Stockholm University and published in Cell, combined preclinical animal experiments with an early human phase 1 trial. In animals, compound 15 improved fat oxidation, controlled blood glucose and preserved skeletal muscle mass. In the phase 1 clinical portion, the drug was generally well tolerated in 48 healthy volunteers and 25 people with type 2 diabetes, with fewer reported gastrointestinal side effects than commonly associated with GLP-1 therapies.

"Muscles are important in both type 2 diabetes and obesity, and muscle mass is also directly correlated with life expectancy."

How It Works

Compound 15 is a novel beta-2 adrenergic agonist engineered to enhance muscle metabolic activity while minimizing the cardiac overstimulation that limited older drugs in this class. By acting directly on muscle tissue to raise metabolic rate, the compound aims to shift energy use toward fat burning rather than relying solely on appetite suppression.

"This compound’s mechanism of action could address some specific metabolic concerns with previous weight reduction therapies, such as the loss of both muscle and fat tissue," a doctor said.

“Our results point to a future where we can improve metabolic health without losing muscle mass,” said Tore Bengtsson, professor at the Department of Molecular Bioscience, Wenner-Gren Institute, Stockholm University.

Expert Reaction and Limitations

External experts welcomed the concept but urged caution. Dr. Trey Wickham, interim chief of Endocrinology, Diabetes & Metabolism at VCU Health, emphasized that larger and longer trials are required to confirm long-term safety and clinical efficacy, noting that early human results are promising but preliminary.

The investigators acknowledged limitations: mouse models cannot fully capture the complexity of human obesity and diabetes, structural studies are needed to define the compound’s precise mechanism, and phase 1 trials do not yet provide conclusive evidence on long-term glucose control or weight outcomes.

Next Steps

Atrogi AB, the company developing the drug, plans a larger phase 2 trial that will enroll a more diverse population, including people with obesity. The research received support from the Swedish Research Council, the Swedish Society for Medical Research and the Novo Nordisk Foundation and included collaborators at Uppsala University, the University of Copenhagen, Monash University and the University of Queensland.

Bottom line: Compound 15 is an intriguing oral candidate that targets muscle metabolism to promote fat burning while preserving muscle mass, but its role as a safe and effective treatment for diabetes or obesity will depend on results from larger, longer clinical trials.