New Weight Loss Drug Works Like an Exercise Pill

The weight loss drug revolution appears to have truly arrived. For decades, there have been compounds available that reduce weight or strengthen muscles, but they always have dangerous side effects and worsen long-term health. The compensation simply wasn’t worth it. A weight loss pill still seemed far away.

Now, drugs like Ozempic (semaglutide) and Mounjaro (tirzepatide) – supported by large, time-consuming clinical trials – cause weight loss of 12% to 18% and dramatically reduce the risk of death from heart disease, with minimal side effects. They are currently available in injection form, but tablet forms are on the way.

These medications help users lose weight by drastically reducing appetite and therefore caloric intake. Scientists are also looking for pharmaceuticals that affect the other side of the weight loss coin: calorie expenditure. In short, they would make the body act as if it were exercising. A team, led by researchers at Washington University in St. Louis, is currently testing a potential candidate.

Exercise pill

Its weight loss medication, SLU-PP-332, acts on estrogen receptor-related receptors (ERRs), found in energy-intensive tissues such as skeletal muscles, liver, and heart. When active, these receptors trigger metabolic changes associated with exercise, such as increasing the muscles’ ability to consume oxygen, increasing the breakdown of fat for energy, and speeding up metabolism.

In a study published earlier this year, the research team administered SLU-PP-332 to healthy mice and found that they could run 70% longer and 45% further than mice that did not receive the drug.

In a more recent study published late last month, they tested SLU-PP-332 again in rats, this time to observe its effects on weight control and metabolism. They administered the drug to obese mice fed a high-fat diet and gave others a placebo for four weeks. At the end of the study, mice receiving SLU-PP-332 weighed 12% less than their control counterparts, despite eating the same amount of food. It is important to highlight that all the difference in weight came from the reduction in fat mass – there was no difference in lean mass. The rats taking the weight-loss drug simply used more energy, mostly from body fat. There were no serious side effects.

“This compound basically tells skeletal muscle to make the same changes that you see during resistance training,” said Thomas Burris, professor of pharmacy at the University of Florida and corresponding author of the study. “When you treat mice with the drug, you can see that their entire body’s metabolism switches to using fatty acids, which is very similar to what people use when they are fasting or exercising,” Burris added.

Cautious optimism

SLU-PP-332 still has a long way to go before it can join Ozempic or Mounjaro on the market. At this stage, you are more likely to fail than succeed. Appropriate dosing in humans, balancing side effects and efficacy, can be difficult. Or perhaps longer trials will reveal worrying side effects. Still, the promising preliminary results from SLU-PP-332 further show how safe and effective weight-loss drugs, only recently seen as a pipe dream, are expected to proliferate in the decades ahead for the benefit of millions of people.

This article is reprinted with permission from Big Think, where it was originally published.