Researchers Uncover Surprising New Benefits and Risks of GLP-1 Weight Loss Drugs Ozempic, Mounjaro

BATON ROUGE, La. — Researchers who have spent years studying GLP-1 weight loss medications say some of the drugs’ effects have caught even longtime experts off guard, five years into widespread use of medications such as Ozempic, Wegovy and Mounjaro, according to new findings highlighted by scientists at Louisiana’s Pennington Biomedical Research Center.

Dr. Steven Heymsfield, a professor at Pennington Biomedical Research Center and director of its Metabolism Body Composition Laboratory, has studied GLP-1 drugs for 15 years. He said the range of effects researchers have documented has included both expected and unexpected findings. “Some were predicted beforehand and others were completely surprising,” Heymsfield said. “So for example, we know that people who are obese have a higher risk of diabetes.”

Among the more unexpected discoveries, Heymsfield pointed to reports from patients describing a diminished desire to drink alcohol while taking the medications, an effect that has since gained scientific support. “The unpredictable type is that people report less desire to drink alcohol,” Heymsfield said. “And now there are studies beginning to show that that’s been confirmed.” That observation aligns with a broader body of emerging research; according to Forbes Health, a 2026 study published in BMJ examining more than 600,000 veterans with Type 2 diabetes found that GLP-1 medications were associated with a decreased risk of substance use disorders across all major drug classes, as well as fewer overdoses and hospitalizations among those with existing substance use disorders, compared with a different class of diabetes medication known as SGLT-2 inhibitors. Forbes Health noted that GLP-1 receptors are present in brain regions that influence impulse control and reward signaling, a mechanism researchers believe may help explain the reduced pleasure-seeking behavior associated with addictive substances. The outlet cautioned, however, that this research remains preliminary, and GLP-1 medications are not currently FDA-approved for treating substance use disorders specifically.

Heymsfield also highlighted improvements reported by patients with arthritis, describing reduced pain, less inflammation and improved mobility among users of the drugs. “People with arthritis have unexpectedly reported improved symptoms, less pain and less inflammation, and can walk better,” Heymsfield said, adding that studies have shown patients on the medications have needed fewer knee replacement surgeries as a result. That finding is echoed in more detailed clinical research presented at the American Diabetes Association’s 2026 conference, according to coverage from the American Journal of Managed Care, which reported that knee osteoarthritis outcomes improved with semaglutide, including meaningful reductions in pain scores and decreased use of pain medication, with tirzepatide’s greater overall weight loss producing similarly meaningful pain benefits.

Cardiovascular improvements represent another area where Heymsfield said the evidence has grown increasingly robust. “We’ve already shown with GLP-1s that it reduced the risks of heart attacks, cardiovascular disease, mortality,” he said, adding that researchers believe the benefit extends beyond simple weight loss. “And it’s thought that it’s not just the weight loss, but processes like inflammation also are improving that might mediate these effects on the heart.” That assessment aligns closely with a large international review published earlier this year and highlighted by ScienceDaily, in which researchers at Anglia Ruskin University analyzed data from more than 90,000 patients across major international clinical trials and found that GLP-1 weight-loss drugs such as semaglutide significantly lowered the risk of heart attacks, strokes, heart failure and premature death over multiple years of treatment, leading researchers to suggest the medications could ultimately become a major tool against cardiovascular disease more broadly, not solely obesity and diabetes.

Heymsfield emphasized that not every benefit observed in patients appears to be directly tied to weight loss itself. “It looks like it’s not just the weight loss, but these drugs that actually have themselves some properties that improve inflammation,” he said, noting that researchers are actively continuing to study that distinct anti-inflammatory mechanism. He also pointed to a phenomenon frequently reported by patients known as reduced “food noise,” describing it as a diminished preoccupation with thoughts about food throughout the day, a change some patients describe as a significant improvement in daily quality of life. At the same time, Heymsfield noted a more complicated emotional dimension to that same effect: for some patients, the medications’ dampening of food-related pleasure has led them to discontinue use altogether. “And if you lose that enjoyment, some people go off the drugs because they’ve lost that part of their life,” he said.

Alongside these benefits, Heymsfield and other researchers have continued to flag significant risks and open questions surrounding long-term use of the medications. Muscle and bone loss remain a consistent concern across virtually all patients using the drugs, according to Heymsfield, who said this side effect occurs in essentially everyone who loses weight while taking GLP-1 medications, regardless of other individual factors. He said researchers at Pennington are actively studying strategies to mitigate that loss, including increased dietary protein intake and resistance exercise training. That concern is echoed in more technical detail by a recent analysis published in the American Journal of Managed Care, which noted that higher-dose incretin therapies can drive lean-mass losses accounting for anywhere from roughly 25% to 40% or more of a patient’s total weight reduction, a dynamic that reduces resting energy expenditure and requires proactive assessment of sarcopenia risk, the medical term for age- or illness-related muscle loss. The same analysis pointed to supervised resistance and aerobic training combined with adequate protein intake, generally in the range of 1.2 to 1.6 grams per kilogram of body weight daily, as an evidence-based approach shown to help preserve or even increase lean muscle mass in patients using the medications.

Separate research from Washington University School of Medicine and the Veterans Affairs St. Louis Health Care System, published in January 2025, similarly identified a mixed picture of benefits and risks associated with the drugs. That research found GLP-1 medications were tied to decreased risk of dementia and addiction, alongside cognitive and behavioral health benefits, but also identified increased risk of certain gastrointestinal problems, along with kidney and pancreas conditions, including pancreatitis, among some users.

The rapid rise in GLP-1 medication use over the past several years has made these evolving findings increasingly relevant to a large and growing share of the American public. According to Forbes Health, roughly one in eight Americans has already used or is currently using GLP-1 medications to treat conditions including diabetes, heart disease or obesity, with some projections suggesting as many as 30 million Americans could be using the drugs by the end of the decade. Originally approved by the FDA specifically to treat Type 2 diabetes, GLP-1 medications have since expanded into treatment for a widening range of conditions, including cardiovascular risk reduction, obstructive sleep apnea, chronic kidney disease and liver disease, alongside their most commonly recognized use for weight loss, even as researchers continue actively investigating additional off-label applications, including potential treatment for addiction and binge eating disorder, through ongoing clinical trials.

As the body of research on GLP-1 medications continues to expand rapidly, scientists including Heymsfield have emphasized that understanding of both the benefits and risks associated with long-term use remains an active and evolving area of study, with researchers continuing to work toward strategies that can help patients preserve muscle and bone health while benefiting from the medications’ broader metabolic, cardiovascular and potentially neurological effects.