Weight-loss drugs affect patients differently

In clinical trials, researchers found that GLP-1 drugs like Wegovy and Zepbound helped patients lose at least 10% of their starting weight. However, new research suggests that the real-world efficacy of these drugs is lower than the clinical trial data suggests.

In a new report from Dandelion Health, researchers analyzed EHR data from almost 17,000 patients who were prescribed a GLP-1 drug between 2019 and 2023. Although the patients on GLP-1 drugs lost around twice as much weight as similar patients who weren't prescribed GLP-1s, the amount of weight lost was relatively small.

On average, patients on GLP-1 drugs lost around 1.4% of their starting body weight after three months. After a full year of treatment, patients lost an average of 3% of their body weight. Among those on GLP-1 drugs, only 10% had similar results to clinical trial findings. An additional 10% saw no weight change or even gained weight over time.

"There are some people who are under-responders, there are some people who are over-responders, and there's some that respond as expected to the medication," said Disha Narang, an endocrinologist and director of obesity medicine at Endeavor Health. "Studies are still happening to understand why."

Many patients don't stay on weight-loss drugs long enough to see results

At the same time, many patients often don't stay on weight-loss drugs long enough to see results.

In a new study of roughly 170,000 Blue Cross Blue Shield beneficiaries who were prescribed GLP-1 drugs between 2014 and 2023, almost 60% were on them for less than 12 weeks. And around 30% of patients who were prescribed these drugs stopped taking them after the first month.

 "These are long-term medications to treat a chronic disease," Narang said. "This is absolutely a marathon, not a sprint. And when we do treat this as a sprint, I think patients are likely to get off of medication much faster."

According to health experts, impatience with results may be one reason patients choose to stop treatment. In a new KFF poll, only half of people who had stopped taking weight-loss drugs said they felt they were effective, compared to almost 75% of people who were currently on the treatments.

Side effects, including nausea, diarrhea, vomiting, and constipation, may also deter some patients from continuing the drugs. According to data from the longest clinical trial of Wegovy, 17% of participants left the trial due to side effects.

Patients will also likely have to be on these treatments long-term to sustain their weight loss. In one early study, patients regained two-thirds of the weight they lost within the first year of stopping treatment. Separately, a new analysis found that only 17% of people who were on weight-loss drugs were able to maintain 80% of their weight loss after stopping treatment.

The potential to regain weight after stopping treatment can also be a deterrent for patients. In a 2023 KFF poll, only 14% of respondents said they were still interested in weight-loss drugs after learning that people tend to regain weight once they stop taking the drugs.

To help patients address these deterrents, health experts say appropriate counseling from a provider is needed. According to Razia Hashmi, VP of clinical affairs for the Blue Cross Blue Shield Association, each additional follow-up visit with a provider increased a patient's chances of sticking with a weight-loss treatment by 60%.

"If you don't have frequent touchpoints, frequent interactions, then it's really it's hard to manage side effects. It's hard to manage expectations. It's hard to see if there's improvement in some of these other metabolic comorbidities," said Jody Dushay, an endocrinologist at Beth Israel Deaconess Medical Center and assistant professor of medicine at Harvard Medical School.

"There's not a line in the sand for every single person," Dushay added. "Physicians and patients have to just look at all the data and make a decision about treatment together."

Advisory Board's weight-related resources

To help you address the growing use of weight management drugs, Advisory Board offers several resources:

This expert insight outlines the five biggest questions about weight management drugs and their answers. Similarly, this expert insight addresses what headlines get wrong about weight management drugs and what healthcare leaders should know instead.

Radio Advisory's Rachel Woods has also covered GLP-1 drugs on the podcast, discussing the potential future of these drugs and how they could help — or hurt — health systems' finances. Other useful resources include this expert insight on the five catalysts that will impact the future of obesity care and this research on three potential pathways for the future of obesity care.

Our weight management and obesity care resource library can also help leaders understand the current care landscape, manage innovations, and prepare for transformations in care. (McPhillips, CNN, 5/21; Noguchi, "Shots," NPR, 5/27; Tozzi, Bloomberg/Modern Healthcare, 5/28)