Research raises concerns about the effects of weight loss drugs on bone density
New evidence suggests widely used GLP-1 weight-loss drugs may weaken bone density
Obesity is widely recognized as a major public health challenge in the United States, a condition that has significant consequences for both physical and mental health. When a new class of drugs promising rapid weight loss emerged, it seemed too good to be true. Unfortunately, later evidence suggests that might have been exactly the case.
New research has raised concerns about the potential impact of these widely used GLP-1 weight-loss drugs, which were originally developed to treat diabetes, on bone health. At the American Academy of Orthopaedic Surgeons’ annual conference in New Orleans on March 2, Dr. John Horneff of the University of Pennsylvania presented findings suggesting that patients using GLP-1 medications may face a 30% higher risk of developing osteoporosis, a condition that weakens bones and increases fracture risk. “It’s not huge, but within that data that was put in there, you even saw nearly a doubling of the risk of having some sort of bone mineral density issue at five years,” Horneff said.
In the United States, osteoporosis already contributes to roughly 1.5 million fractures each year; as these medications become more widely used, experts warn that the number of osteoporosis-related fractures could rise as well.
Across Boston, advertisements for GLP-1 medications are nearly impossible to miss. They appear in Super Bowl commercials and on billboards, trains, social media feeds, and magazine pages. Across all of them, one face appears again and again: Serena Williams, widely regarded as one of the greatest female athletes in history. In Boston’s South Station, the city’s busiest train station, a towering advertisement just beside the train schedule features Williams appearing to inject Ro, a GLP-1 medication, into her arm.
For decades, unrealistic body standards have shaped how women see themselves. Magazine editors have long altered images of already thin models to make them appear slimmer, while dolls often portray bodies that are biologically unattainable. These pressures begin early: according to the National Eating Disorders Association, 40–60% of elementary school girls are concerned about their weight. However, Serena Williams represents a level of performance often associated with peak physical fitness, shaped by years of strength, discipline, and training. She has said herself, “I’m not a size 2. It’s okay to look strong and be strong.” Yet portraying an athlete of her caliber as someone who still needs medication to become thinner sends a contradictory message. As Jean Kilbourne, a media critic who has spent her career examining the impact of advertising on women’s self-image, explained, advertising doesn’t just sell products: “It sells values, images, and concepts of who we are and who we should be.”
Williams’s partnership with Ro suggests that despite years of training and careful attention to diet, Williams’s body is still not good enough on its own. For young girls who look up to her, this can reinforce the idea that achieving the “perfect” body requires medication or for those without access to it, extreme behaviors such as starving themselves. The findings presented at the conference build on a growing body of research suggesting a link between GLP-1 medications and reduced bone density.
For instance, a study published in The Journal of the American Medical Association in April 2024 examined how GLP-1 medications affect bone mineral density. Participants followed a controlled diet and were assigned to GLP-1 medication alone, exercise with a placebo, or a combination of GLP-1 medication and exercise. While the combination group experienced the greatest weight loss, both groups receiving GLP-1 medications showed significant decreases in bone mineral density, particularly in the hip and spine — areas critical for mobility and athletic performance.
Lower bone density could have serious implications for athletes. Research published in the Orthopaedic Journal of Sports Medicine found that runners with reduced lumbar spine bone density — the lower back region that bears much of the body’s weight, and one of the areas most affected by GLP-1 use — were significantly more likely to develop stress fractures. Reduced bone density has also been linked to slower recovery, decreased mobility, chronic pain, and increased fracture risk.
For Serena Williams, the motivation behind the campaign was personal. She has spoken openly about struggling to lose weight after pregnancy despite intense training. After beginning treatment through Ro, she reported losing 31 pounds and said the medication helped her return to her pre-pregnancy performance. She has also cited improvements in other health markers, including reduced cholesterol.
However, the broader message these advertisements send remains complicated. For young women looking up at the image, the takeaway may not be about medical recovery after pregnancy or metabolic health, but about the pressure to lose weight or to use Ro to become more like Serena Williams. Pharmaceutical companies argue that their role is to develop and market medications, not determine how individuals ultimately use them. Still, drug manufacturers often face criticism over high prices and concerns that profit can take priority over patient well-being. In that context, the involvement of Williams’ husband, Alexis Ohanian, as an investor in Ro raises additional questions about the commercial interests surrounding the campaign.
As GLP-1 medications become more widely used, the question facing society is not simply whether these drugs work. It is also what message they send to young athletes, to people struggling with body image, and to a culture that has long equated thinness with success. Before the next generation grows up with worsening body image pressures and the potential health risks associated with weight-loss medications, many experts argue that the public should pause and consider the full picture.