Why most people stop GLP-1s within a year (and who stays on)

When you read that a GLP-1 produced 15% or 20% weight loss, that number describes the people who kept taking it. The trials are built to keep participants on the drug, with free medication, close monitoring, and support. Outside a trial, the picture is very different, and it is the part almost no one puts in the ad.

How many people stop

The numbers are sobering, and consistent across sources:

• A large pharmacy-benefit analysis by Prime Therapeutics found about 71% of people taking a GLP-1 for obesity had stopped within a year, and 85% within two years.
• A peer-reviewed study of commercially insured adults (Journal of Managed Care & Specialty Pharmacy, 2024) found that in the first year, about two-thirds had a gap of more than 60 days, and only 27% stayed adherent.
• Other analyses put the one-year figure closer to half. Blue Health Intelligence reported that roughly 30% stop within the first month alone.

Why they stop

The reasons are not what most people assume. It is rarely “the drug did not work.”

• Cost and insurance, the leading reason. Across studies, affordability and losing coverage were the most common driver at nearly every point. People who stop for cost tend to do so later, once an intro price ends, a plan changes, or a prior authorization lapses.
• Side effects, a close second. The gastrointestinal effects (nausea, vomiting, diarrhea, constipation) are severe enough to prompt stopping in an estimated 10% to 20% of users. Side-effect stops tend to happen early, in the first weeks. Our first-month guide covers what that stretch is usually like.
• Reaching a goal, availability, and switching. Some people stop because they hit a target weight (and then often regain, more on that below); others get caught by shortages or are switched between drugs by their prescriber.

Who stays on

Persistence is not random. The clearest split is by diagnosis:

People taking a GLP-1 for type 2 diabetes stay on longer than people taking it for weight loss. One analysis found 13-month persistence of about 41% for diabetes versus 32% for weight loss, and weight-loss patients were also less likely to restart after stopping. The main reason is not motivation, it is access: diabetes coverage is broader and steadier, so the drug is easier to keep getting. That access gap is the throughline of this whole topic.

What happens when you stop (it is more nuanced than the trials)

The trials tell an alarming story about stopping: when semaglutide was withdrawn in the STEP 1 extension, participants regained about two-thirds of the weight they had lost. That is real, and we cover the physiology in what happens when you stop a GLP-1.

But the real world looks gentler on average, for a revealing reason. A Cleveland Clinic cohort (Gasoyan and colleagues) found that among people who discontinued, the average weight change a year later was small: those treated for obesity had lost about 8.4% and regained only about 0.5% a year after stopping. The catch is why. About 1 in 5 restarted the medication and about 1 in 3 switched to another treatment. So the modest average regain is not evidence that stopping is safe; it is evidence that a lot of people who “stop” do not stay stopped.

The practical takeaways

If the biggest reason people fail on these drugs is cost and access, then staying on is mostly a coverage problem to solve, not a willpower one:

• Know your real cost before you start, so an intro price does not surprise you into quitting. See our real cost of a GLP-1 breakdown.
• Lock in the cheapest sustainable route. Check whether your state’s Medicaid covers it on the state coverage page, or whether the new Medicare $50 Bridge fits (and plan for it ending in 2027). If a plan denies you, our prior-authorization and appeal templates help.
• Go in expecting the early side effects, which are the other main reason people quit in the first weeks and which often ease with time.

The headline number is the one worth remembering: for every person still losing weight on a GLP-1 a year in, one or two others have already stopped, usually because they could not afford to keep going. If you want to be in the first group, plan for cost first. Start with the am I a candidate? check, then compare the real options on /compare.