What happens to your blood sugar if you stop a GLP-1 with prediabetes?

Key takeaways

Dr. Linda's take

This is the question underneath the question. Women rarely ask me "what happens if I stop." They ask "is this forever?" And what they mean is: am I fixing something, or am I renting a result?

I am going to answer it with actual numbers, because you can handle them, and because the vague version of this answer is how people end up blindsided. The short version is that stopping tends to undo much of what you gained, that this is not a personal failure, and that the picture is not all-or-nothing.

What happened when people in the trials stopped?

We have unusually good data here, because researchers deliberately took the medication away and watched.

In the STEP 1 extension, mean weight loss from week 0 to week 68 was 17.3% with semaglutide, and following treatment withdrawal participants regained 11.6 percentage points of lost weight by week 120, resulting in a net loss of 5.6% from where they started.

Read that carefully, because both halves matter. Most of it came back. And a net 5.6% was still there a year later. Both of those things are true at once.

The tirzepatide data tells the same story. In SURMOUNT-4, the mean percent weight change from week 36 to week 88 was -5.5% with tirzepatide versus 14.0% with placebo. People who stopped gained; people who continued kept losing.

And in STEP 4, with continued semaglutide the mean body weight change from week 20 to week 68 was -7.9% versus +6.9% with the switch to placebo. Worth knowing: everyone in that trial was receiving lifestyle support the whole time. The regain happened anyway. If you have ever been told you just need more discipline, that finding is your evidence otherwise.

Does my blood sugar come back too?

This is the part you actually asked about, and there is now a direct answer.

A post hoc analysis of SURMOUNT-4 tracked HbA1c against how much weight people regained after stopping. HbA1c rose by 0.14% in those who regained less than a quarter of their lost weight, and by 0.35% in those who regained three-quarters or more.

So blood sugar tracked the weight. The more came back, the more the number moved. That is a gradient, not a cliff, and it is the most useful thing in this entire article.

The STEP 1 extension found the same directionally: cardiometabolic improvements seen from week 0 to week 68 with semaglutide reverted towards baseline at week 120 for most variables. Note the precise words. Reverted towards baseline. For most variables. Not "all the way back," and not "for everything."

But I saw that most people with prediabetes get back to normal blood sugar

You did, and that number is real. It is also routinely stripped of the one word that changes its meaning.

Across the STEP program, significantly more participants with prediabetes at baseline had normoglycemia at week 68 with semaglutide versus placebo, at 84.1% versus 47.8% in STEP 1.

That is a genuinely impressive result. Now the fine print, which the researchers themselves put in the paper: it was measured at week 68, before the washout period, while participants were still on treatment.

So 84.1% is not a durability number. It tells you what happens while you are taking it. It does not tell you what happens after. And notice the placebo column: 47.8% of people reached normal blood sugar with lifestyle support alone. Nearly half. That is not nothing, and it deserves saying out loud.

I want to be honest about a gap. No trial I can find reports what proportion of people who reached normal blood sugar on one of these medications fell back to prediabetes after stopping. It is the number everyone wants. It does not appear to exist yet. For the other direction of this question, see can a GLP-1 reverse prediabetes.

Is any of it mine to keep?

Yes, and this is the part I most want you to hear, because the rest of this article is heavy.

In that same SURMOUNT-4 analysis, changes at week 88 in waist circumference, non-HDL cholesterol, and fasting insulin in those with less than 25% weight regain were not significantly different compared with week 36.

Read that again. The people who held onto most of their loss also held onto their waist, their cholesterol, and their fasting insulin. The metabolic reversal was not automatic. It tracked the regain.

Now the caveat I owe you, because I will not oversell this: that is a post hoc, observational finding inside a trial. It shows an association. It does not prove that anything a person did caused the low regain, and it cannot promise that if you do the right things you will keep the benefit. Even that group saw HbA1c rise by 0.14%.

But the shape of it is real. This is not a switch that flips off the moment you stop.

Would lifestyle alone have fixed it?

This deserves a straight answer, because it is what people are quietly hoping.

In the Diabetes Prevention Program, an intensive lifestyle intervention reduced the incidence of type 2 diabetes by 58% and metformin by 31% compared with placebo, over an average of 2.8 years. That is one of the most important results in modern medicine, and the population looked a lot like the women I see: 68% women, 45% from minority groups, mean age 51.

Then they followed those people for fifteen years. Diabetes incidence was still reduced by 27% in the lifestyle group and 18% in the metformin group, with declining between-group differences over time, and at year 15 the cumulative incidences of diabetes were 55% in the lifestyle group, 56% in the metformin group, and 62% in the placebo group.

Sit with those numbers. The best lifestyle program ever run, and most people in it developed diabetes anyway. The gap narrowed from 58% to 27%. That is not an argument against lifestyle. It is an argument against the fantasy that any intervention is a one-time cure, and it is the same lesson the medication data teaches.

Delay is still worth having. Those who did not develop diabetes had a 28% lower prevalence of microvascular complications. Time without diabetes is not a consolation prize.

What does this actually mean?

The STEP 1 investigators put it plainly: their findings confirm the chronicity of obesity and suggest ongoing treatment is required to maintain improvements in weight and health.

That sentence lands hard the first time you read it. But turn it around. Nobody thinks you failed at blood pressure because your reading went back up when you stopped your blood pressure medication. We do not describe that as willpower. This is the same category of thing, and the trials keep saying so.

Questions worth bringing to a clinician: what would we watch if we ever changed or stopped this, how often should my blood sugar be checked, and what does the off-ramp look like if we get there? Those are planning questions, not failure questions. If you are still working out whether you qualify, see do you qualify for a GLP-1 if you have prediabetes but not diabetes or take our eligibility quiz.

One honest limitation on everything above: these trials were not designed as prediabetes trials. People with prediabetes were a subgroup within them. The trajectory is inferred from adjacent evidence, and you deserve to know that rather than be handed false precision.

The honest bottom line

What happens to your blood sugar if you stop? On the best evidence available, it drifts back in proportion to the weight that returns. Not instantly, not completely, and not equally for everyone.

What it does not mean is that the work was wasted or that you were sold something fake. Prediabetes is a long game. This is a chronic condition being managed, not a project you finish. Knowing that in advance is not the bad news. It is the thing that lets you plan instead of being ambushed.

Frequently asked questions

Does blood sugar go back up if I stop?

It tends to track the weight that returns. A post hoc analysis of SURMOUNT-4 found HbA1c rose by 0.14% in those who regained less than a quarter of their lost weight, and by 0.35% in those who regained three-quarters or more.

Will I regain the weight?

Most of it, on average, though not all. In the STEP 1 extension, mean weight loss from week 0 to week 68 was 17.3% with semaglutide, and following treatment withdrawal participants regained 11.6 percentage points of lost weight by week 120, resulting in a net loss of 5.6% from where they started.

Does the 84.1% normoglycemia figure mean prediabetes is cured?

No. Across the STEP program, significantly more participants with prediabetes at baseline had normoglycemia at week 68 with semaglutide versus placebo, at 84.1% versus 47.8% in STEP 1. That was measured before the washout period, while participants were still on treatment, so it is not a durability figure.

Can I keep any of the benefit after stopping?

Possibly, and it appears to track how much weight stays off. In the SURMOUNT-4 analysis, changes at week 88 in waist circumference, non-HDL cholesterol, and fasting insulin in those with less than 25% weight regain were not significantly different compared with week 36. This is a post hoc, observational finding, so it shows an association rather than proving cause.

Would lifestyle changes alone have been enough?

They help and they are rarely a permanent fix on their own. In the Diabetes Prevention Program, an intensive lifestyle intervention reduced the incidence of type 2 diabetes by 58% and metformin by 31% compared with placebo, over an average of 2.8 years. At year 15 the cumulative incidences of diabetes were 55% in the lifestyle group, 56% in the metformin group, and 62% in the placebo group.

Is stopping a failure?

The STEP 1 investigators put it plainly: their findings confirm the chronicity of obesity and suggest ongoing treatment is required to maintain improvements in weight and health. That describes a chronic condition being managed, not a personal shortcoming.

References

1. Diabetes, obesity & metabolism (2022). Weight regain and cardiometabolic effects after withdrawal of semaglutide: The STEP 1 trial extension. PubMed PMID 35441470. https://pubmed.ncbi.nlm.nih.gov/35441470/ (Accessed 2026-07-17).
2. JAMA internal medicine (2026). Cardiometabolic Parameter Change by Weight Regain on Tirzepatide Withdrawal in Adults With Obesity: A Post Hoc Analysis of the SURMOUNT-4 Trial. PubMed PMID 41284285. https://pubmed.ncbi.nlm.nih.gov/41284285/ (Accessed 2026-07-17).
3. Diabetes care (2022). Changes in Glucose Metabolism and Glycemic Status With Once-Weekly Subcutaneous Semaglutide 2.4 mg Among Participants With Prediabetes in the STEP Program. PubMed PMID 35724304. https://pubmed.ncbi.nlm.nih.gov/35724304/ (Accessed 2026-07-17).
4. The lancet. Diabetes & endocrinology (2015). Long-term effects of lifestyle intervention or metformin on diabetes development and microvascular complications over 15-year follow-up: the Diabetes Prevention Program Outcomes Study. PubMed PMID 26377054. https://pubmed.ncbi.nlm.nih.gov/26377054/ (Accessed 2026-07-17).
5. JAMA (2024). Continued Treatment With Tirzepatide for Maintenance of Weight Reduction in Adults With Obesity: The SURMOUNT-4 Randomized Clinical Trial. PubMed PMID 38078870. https://pubmed.ncbi.nlm.nih.gov/38078870/ (Accessed 2026-07-17).
6. JAMA (2021). Effect of Continued Weekly Subcutaneous Semaglutide vs Placebo on Weight Loss Maintenance in Adults With Overweight or Obesity: The STEP 4 Randomized Clinical Trial. PubMed PMID 33755728. https://pubmed.ncbi.nlm.nih.gov/33755728/ (Accessed 2026-07-17).
7. The New England journal of medicine (2002). Reduction in the incidence of type 2 diabetes with lifestyle intervention or metformin. PubMed PMID 11832527. https://pubmed.ncbi.nlm.nih.gov/11832527/ (Accessed 2026-07-17).

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*This article is general education and is not medical advice. It cannot tell you what is right for your body. Talk with a licensed clinician about your own situation.*

*Written and clinically reviewed by Dr. Linda Moleon, MD. Last reviewed 2026-07-17.*