New Weight-Loss Drug Mimics Exercise to Burn Fat

Imagine if you could get all the benefits of exercise by just popping a pill? It might sound like science fiction, but researchers in Florida may have engineered just that.

The new drug, so far tested on mice, leads to controlled weight loss by convincing the body's muscles that they are exercising more than they actually are, providing an exciting alternative to weight loss drugs like Ozempic and Wegovy.

"Drugs like Ozempic and Mounjaro act primarily by limiting hunger (reduced food intake), whereas this class of drug increases the metabolic activity of muscle, mimicking the effects of exercise without affecting food intake," Thomas Burris, a professor who has led the research into the drug at the University of Florida, told Newsweek. "This drug increases resting energy expenditure, which is also observed when an individual exercises. The physiological changes in the muscle are also similar to what is observed under conditions of repeated aerobic exercise."

"When you treat mice with the drug, you can see that their whole body metabolism turns to using fatty acids, which is very similar to what people use when they are fasting or exercising. And the animals start losing weight."

Not only does this compound, known as SLU-PP-332, increase resting metabolism, but it also improves muscle function and endurance, unlike the weight loss drugs on the market today. Previous research by Burris and his team in March found that healthy weight mice given this drug ran 70 percent longer and 45 percent further than those not receiving the compound.

In their latest study, published in the Journal of Pharmacology and Experimental Therapeutics on September 27, the team tested the drug in obese mice. They found that they could run 50 percent further than before, as well as gaining 10 times less fat than untreated mice during the month-long study period, and they lost 12 percent of their body weight despite eating the same quantity of food and doing the same amount of exercise.

"They use more energy just living," Burris said.

However, patients receiving this drug would still be encouraged to exercise, if it was safe to do so.

Enhancing the Effects of Exercise

"There are likely additional benefits of exercise beyond what this class of drug induces," Burris said. "We are still investigating this, but it is also likely that these drugs will enhance the effects of at least some limited exercise activity as well."

And, like exercise itself, the beneficial effects of these compounds would wear off after stopping the drug, highlighting the importance of establishing healthy lifestyle habits.

"It is important to reinforce that these drugs were developed with treating diseases in mind rather than developing a 'replacement' for exercise," Burris said. "In addition to treating type 2 diabetes and obesity, they may be useful for treating muscle-wasting that is normally associated with aging and various genetic diseases associated with decreased muscle function (e.g. muscular dystrophy). We also now know that they are very effective in treating heart failure in animal models by directly targeting the abnormal metabolic function that arises when the heart fails."

So how does it work? SLU-PP-332 targets a group of proteins in the body called estrogen-related receptors, or ERRs. These proteins are involved in activating important metabolic pathways in energy-hungry tissues like muscles, the heart and the brain, and have been shown to be more active during exercise. What SLU-PP-332 does is target these receptors and tricks them into thinking the body is exercising when it isn't.

Such a drug also has the potential to be abused by people wanting to achieve unhealthy weight loss goals or those wanting to enhance their athletic performance.

"We expect that drugs such as these exercise mimetics would have significant abuse potential," Burris said. "This could be to lose weight beyond what is healthy or for performance enhancement. The drug would be by prescription only, and medical providers would be the first line of defense against inappropriate use. Like other drugs that enhance athletic performance, I would expect drugs like this class to be on a banned list (and tested for) by various professional/Olympic agencies."

Safety considerations must also be addressed, although so far the team have observed no severe side effects.

"One of our general concerns is the potential for increasing energy expenditure to dangerous levels, but what we have noticed is that these drugs appear to be self-limiting to the level that natural exercise would induce," Burris said. "Of course, we are still investigating potential side effects, and this is an important area as we develop these towards clinical trials."

If all goes well, these drugs could be available in as little as five years. "We are currently optimizing these drugs for evaluation of their activity in future clinical trials in patients," Burris said. "Although they may be in patients within the next two years or so, these would be clinical trials prior to FDA approval that would take several more years. We are likely looking at least five years until there is potential for them to be on the market."