How long do people stay on GLP-1s?

Plan on years, because months usually isn’t enough. Semaglutide and tirzepatide are medicines for a long-term condition. The trials behind every headline number ran 68 to 72 weeks with no planned stop. Keeping the weight off generally means staying on some dose long-term.

That surprises people who expected something closer to a course of antibiotics.

The trials assume you don’t stop

STEP 1 (Wilding et al., NEJM 2021, n=1,961) put people on weekly brand-name semaglutide (Wegovy) 2.4 mg for 68 weeks. They lost 14.9% of their body weight, compared with 2.4% on placebo. SURMOUNT-1 (Jastreboff et al., NEJM 2022, n=2,539) ran brand-name tirzepatide (Zepbound) for 72 weeks. People on the 15 mg dose lost 20.9%. In both trials, the final week is when the measuring stopped. It isn’t when people were meant to stop the medicine.

The longest look we have is SELECT (Lincoff et al., NEJM 2023, n=17,604). People who already had heart disease stayed on brand-name semaglutide (Wegovy) for more than three years on average. Their risk of major heart events fell 20% in relative terms (HR 0.80). More than three years on the drug, in seventeen thousand people, is also the best long-term safety data these drugs have.

There’s a floor on the timeline, too. Just reaching the full dose takes months. On the Wegovy label, semaglutide titrates (goes up step by step) 0.25 → 0.5 → 1.0 → 1.7 → 2.4 mg, in steps of about four weeks. That’s about 16 weeks to the top dose if side effects don’t slow the ramp. On the Zepbound label, tirzepatide starts at 2.5 mg and goes up every four weeks toward a maintenance dose of 5, 10, or 15 mg. Reaching 10 or 15 mg takes three to five months. If you quit at month three, you’ve mostly experienced the ramp-up and not the drug.

One caveat matters no matter how long you take it. These drugs carry a boxed warning for thyroid C-cell tumors seen in rodents. Whether that applies to humans is unknown. You shouldn’t take them if you or a family member has had medullary thyroid carcinoma or MEN 2. A history of pancreatitis calls for caution, and they aren’t used in pregnancy.

The regain data is the reason

GLP-1 medicines quiet the appetite signals in your brain and slow gastric emptying (how fast food leaves your stomach). Those effects last only as long as the drug is in your system. The drug doesn’t reset your appetite. It holds it down.

The withdrawal trials show what happens when it lets go. In STEP 4 (Rubino et al., JAMA 2021), people on brand-name semaglutide (Wegovy) who switched to placebo at week 20 regained weight. Those who kept going kept losing. SURMOUNT-4 (Aronne et al., JAMA 2024) put numbers on it. Stopping brand-name tirzepatide (Zepbound) meant regaining about 14% of body weight over the next year, and staying on meant losing another 5.5%.

It works like a blood pressure pill. Nobody calls lisinopril a failure because blood pressure climbs when you stop taking it. How fast the weight comes back, whether it’s muscle or fat, and how to slow it are a separate topic, covered in our guide to stopping GLP-1s.

What actually sets your timeline

Four things matter, and they aren’t equally weighted:

• Whether it’s working. Averages hide a wide spread, and some people lose much less than average. If your loss stalls early, your clinician looks at why. Options can include finishing titration or trying a different drug, but neither is automatic.
• Side effects. Nausea, reflux, constipation, and early fullness all follow from slowed gastric emptying. They cluster around dose increases. Your clinician may slow the titration when they show up, instead of stopping outright.
• Cost. By law, regular Medicare Part D can’t cover weight-loss drugs, apart from a temporary program for some brand-name GLP-1s. Many job-based plans leave them out. So a medicine you take for years is often one you pay for yourself. Zappy is cash-pay, and you can use FSA or HSA funds. Current prices for compounded semaglutide and tirzepatide are on each treatment page. Wherever you get it, budget for the timeline the evidence describes.
• Your plan at goal weight. That’s the next section.

At goal weight: continue, maintain, or stop

The evidence is lopsided across the three options.

1. Continue at full dose. This is the best-supported choice. SELECT is more than three years of people doing exactly this, with a heart benefit on top.
2. Drop to a maintenance dose. It’s plausible given how the drug works. But no large trial has tested whether a lower dose holds weight off long-term, so we don’t know where the floor is. Our maintenance dose guide covers what that decision involves.
3. Stop entirely. Expect the pattern seen with brand-name tirzepatide (Zepbound) in SURMOUNT-4 unless your eating, training, and appetite have truly changed underneath the drug. If you go this way, plan the exit with your clinician instead of letting the prescription run out. The dose, the timing, and what to watch for depend on you.

If you’re at the deciding stage, take the quiz, and a clinician will review your case within 24 hours. But settle the timeline question before you start. If you can’t keep the medicine going for at least a year, both in money and in daily life, you’re likely paying for the regain instead of the results.