Experts say the findings highlight a major gap in obesity care: While GLP-1s can help people lose substantial amounts of weight, there are few proven strategies to lock in those improvements once treatment ends.
“This reinforces what we’ve seen across other studies and in real-world practice,” says Yuval Pinto, MD, an obesity and family medicine doctor at Johns Hopkins Medicine in Baltimore, who was not involved in the research. “When a medical intervention that supports weight loss is removed, most people will regain weight.”
How Researchers Studied Weight Regain After GLP-1s
To better understand what typically happens when someone stops taking a weight loss drug, researchers reviewed data from 37 studies that followed more than 9,300 adults after they stopped taking medication for overweight or obesity.
On average, participants had been on treatment for about nine months and were followed for roughly eight months after they stopped. The analysis included older weight loss drugs as well as newer GLP-1 drugs, including Wegovy (semaglutide) and Zepbound (tirzepatide).
Weight Regain Adds Up Month by Month
Across all medications studied, people regained an average of about 0.9 pound (lb) per month after stopping treatment. At that pace, many would be expected to return to their starting weight within 18 months.
For people taking newer GLP-1s, which typically help people lose more weight in a shorter time period, regain was faster, averaging about 1.8 lb per month.
Before starting treatment, people should be aware of this possibility, says Sam West, PhD, a coauthor of the study and a postdoctoral researcher at the University of Oxford in the United Kingdom.
“People need to understand the risk of relatively rapid weight regain if medication stops — that should be part of informed decision-making from the beginning,” he says.
Weight Regain Was Faster After Stoppage of GLP-1s Than After Diet and Exercise Programs
When researchers compared weight regain after medication to what happened after the end of diet and exercise regimens, they found that weight returned about 0.7 lb per month faster after participants stopped medication than after they end a diet and exercise plan — regardless of how much weight people initially lost.
One possible explanation is that medications reduce appetite and calorie intake without requiring people to practice the day-to-day behaviors that support long-term maintenance.
And while people taking GLP-1s who had structured behavioral support (such as instruction on healthy eating, portion control, and exercise) lost about 10 extra pounds overall, it didn’t affect how fast they regained the weight once they stopped medication.
Improvements in Metabolic Health Didn’t Last
Weight wasn’t the only thing affected after treatment stopped.
Although GLP-1 treatment led to improvements in blood sugar, blood pressure, and blood lipids (cholesterol and triglycerides), those gains didn’t last once medication stopped.
Across studies, these health markers returned to unhealthy baseline levels an average of a year and a half after treatment ended.
The results underscore that these medications are metabolic interventions, not just weight loss tools, says Dr. Pinto.
“When weight comes back — and when the medication’s metabolic effects are removed — it’s expected that things like blood sugar or blood pressure will worsen again, especially if people don’t continue lifestyle changes,” he says.
Why So Many People Stop GLP-1 Drugs
The findings are especially relevant because many people don’t stay on GLP-1s long-term.
Affordability is a major issue for many people, says Pinto. “Insurance coverage isn’t forever. In the U.S., it lasts about an average of 16 months — that makes planning for what comes next incredibly important,” he says.
Could New GLP-1 Pills Be the Answer?
One possible way to stop the weight from coming back is to transition to other medications or scale back the dose rather than stop treatment altogether.
In a recent late-stage clinical trial, people who switched from weekly injectable GLP-1 drugs such as Wegovy or Zepbound to the experimental daily GLP-1 pill orforglipron maintained nearly all the weight loss they experienced over one year.
“If cost or insurance coverage is the reason someone stops injectable GLP-1s — and in the U.S., that’s often the main reason — having a more affordable oral option could make a real difference,” Pinto says.
There’s also evidence that de-escalation of dosing — that is, spacing out the doses to every other week or longer, or reducing the dose — may help people keep the weight off once they are in the maintenance phase.
What Patients Should Know Before Stopping — or Starting — a GLP-1
More research is needed on strategies to prevent weight regain after ceasing medication, says Dr. West. Experts agree that you should talk with your doctor before you decide to stop taking GLP-1s.
The takeaway from this analysis shouldn’t be that people should avoid these drugs, says Pinto.
“It’s that weight loss should happen under medical supervision, with frequent follow-ups and a plan for what happens if treatment changes,” he says.
Ideally, that medical supervision would be from an obesity medicine specialist, an expert who goes through a specific medical fellowship to help people lose weight and keep it off, says Pinto.