How Long Can You Sustain Weight Loss on Wegovy? New Research Might Have the Answer

Recent analyses of the longest clinical trial of the weight-loss drug Wegovy have revealed new insights into the drug’s effectiveness. 

One study found that people taking the drug Wegovy sustained weight loss for up to four years and dropped an average of 10% of their body weight during that period. According to another analysis, Wegovy users also showed improvements in heart health irrespective of the amount of weight lost. 

The analyses are based on data from the SELECT trial, which included 17,604 non-diabetics with preexisting cardiovascular disease as well as overweight or obesity. Participants were randomly assigned to receive a placebo or once-weekly injections of Wegovy, which contains the active ingredient semaglutide.

“These findings have important clinical implications,” John Deanfield, a professor of cardiology at University College London who led the study, said in a press release. “Around half of the patients that I see in my cardiovascular practice have levels of weight equivalent to those in the SELECT trial and are likely to derive benefit from taking Semaglutide on top of their usual level of guideline directed care.”

Researchers followed participants for four years—twice as long as previous studies. 

They reported last month in the journal Nature that Wegovy-users continued to lose weight for an average of 65 weeks. 

“At two years, 12% of people on semaglutide reached normal weight status and more than 55% no longer qualified as having obesity BMI class—both observations much higher than placebo,” Donna H. Ryan, MD, a study author and professor emerita at Pennington Biomedical Research Center, told Health.

By 208 weeks, participants had reduced waist circumference by an average of about three inches, dropped an average of 10% of their body weight, and kept the weight off.

The scientists found that weight loss was significant regardless of a person’s sex, race, body size, location, age, and preexisting health conditions.

“We also now have more evidence for semaglutide weight loss efficacy in older, sicker individuals,” Ryan said.

The researchers also found that people taking the drug had fewer serious adverse events than those taking a placebo. However, more people taking Wegovy left the study due to gastrointestinal symptoms, such as nausea and diarrhea.

Ryan said the study showed “weight loss is robust” for people taking Wegovy but slightly less than what previous research into semaglutide has shown. “We expected this because we were not pushing the doses to top-dose in all cases and because it was not a weight loss study,” she said.

The study didn’t examine whether people regain weight once they stop taking Wegovy, as other studies have suggested. “This deserves more research to understand weight loss maintenance strategies,” she said.

In 2023, results from the SELECT trial showed that participants had a 20% lower risk of major adverse cardiovascular events, such as heart attack and stroke. That led the FDA to approve Wegovy to reduce the risk of cardiovascular death, heart attack, and stroke in adults with cardiovascular disease and overweight or obesity (Wegovy was previously only FDA-approved for chronic weight management).

But it has been unclear whether Wegovy’s impact on heart health was due to its effect on weight loss or if another factor was at play.

A separate analysis presented at the European Congress on Obesity in May, however, showed that people had lower odds of developing heart issues regardless of the amount of weight they lost. “This suggests alternative mechanisms of improved cardiovascular outcome beyond reduction in adiposity,” or body fat, the authors wrote. 

Instead of fat reduction, factors such as blood pressure, blood sugar, or inflammation could play a role in improving cardiovascular outcomes, Carlos Sanchez, MD, an expert in cardiovascular disease at OhioHealth Heart & Vascular, told Health.

Sue Decotiis, MD, a New York City weight-loss physician, told Health that the study’s results are significant, but a limitation is that the research didn’t mention the medications participants were taking. “I assume most were on some sort of medications if they had cardiovascular disease,” she said.

The participant pool was also not diverse enough to understand Wegovy’s impact on different populations, according to the authors.