The popularity of GLP-1 weight-loss medications continues to soar—and their uptake is helping to push down obesity rates on a national scale—but a safe, evidence-based way off the drugs isn’t yet in clear view.
An analysis published this week in JAMA Internal Medicine found that most participants in a clinical trial who were assigned to stop taking tirzepatide (Zepbound from Eli Lilly) not only regained significant amounts of the weight they had lost on the drug, but they also saw their cardiovascular and metabolic improvements slip away. Their blood pressure went back up, as did their cholesterol, hemoglobin A 1c (used to assess glucose control levels), and fasting insulin.
In an accompanying editorial, two medical experts at the University of Pittsburgh, Elizabeth Oczypok and Timothy Anderson, suggest that this new class of drugs should be rebranded from “weight loss” drugs to “weight management” drugs, which people may need to take indefinitely.
Some studies have found that about half of people who start taking a GLP-1 drug for weight loss stop taking it within a year—for various reasons—and many people think they can stop taking anti-obesity drugs once they’ve reached a desired weight, Oczypok and Anderson write. But that’s not in line with the data.
“It may be helpful to compare them to other chronic disease medications; patients do not stop their anti-hypertensive medications when their blood pressure is at goal,” they write.
In the trial, researchers—led by Eli Lilly scientists—followed 670 participants with obesity or overweight (but without diabetes) who were treated with tirzepatide for 36 weeks. Then the participants were split into either continuing with the drug for another 52 weeks (88 weeks total) or getting a placebo for that period of time. Both groups were told to continue a reduced-calorie diet and an exercise plan.
In all, 335 participants were randomized to switch to a placebo, and the researchers monitored changes in their weight and cardiovascular health metrics after the switch. Not everyone in the first phase of the trial lost significant amounts of weight on the drug. So, the researchers only closely tracked the 308 of the 335 who lost at least 10 percent of their body weight on the drug.