GLP-1 Medicines and Prediabetes: What Trials Can Tell Us

Prediabetes means blood sugar is higher than the usual range but not high enough to be diagnosed as type 2 diabetes. It signals a higher risk, not a certainty. Many people with prediabetes never develop diabetes, and lifestyle programs have long been shown to lower the risk. Research into GLP-1 and related medicines has added a new question: can these medicines delay progression to type 2 diabetes in people who also have obesity?

What has a trial actually shown?

The clearest data so far come from a three-year extension of SURMOUNT-1, a randomized trial of tirzepatide in adults with obesity. The analysis focused on 1,032 participants who had both obesity and prediabetes and were assigned to tirzepatide (5, 10 or 15 mg weekly) or placebo for 176 weeks, about three and a half years.

• Average weight change ranged from about −12% to −20% with tirzepatide, depending on dose, versus about −1% with placebo.
• 1.3% of people on tirzepatide were diagnosed with type 2 diabetes during treatment, versus 13.3% on placebo.
• Seventeen weeks after stopping, the numbers were 2.4% versus 13.7%, a hint that some of the effect fades once treatment ends.

The most common side effects were gastrointestinal and mostly happened during the first months of dose increases. The study was funded by Eli Lilly, the manufacturer.

What this does and doesn't mean

These results are striking, but they apply to adults with obesity and prediabetes in a closely monitored trial. They don't show that everyone with prediabetes needs a prescription medicine, and they aren't proof of a permanent cure. As of October 2026, no GLP-1 medicine is approved in the US specifically to prevent type 2 diabetes. Some products are approved for type 2 diabetes, some for chronic weight management in eligible people, and some have other specific indications.

Why product indications matter

The same active ingredient can be sold under different brand names with different labels, doses and instructions (for example, Mounjaro and Zepbound both contain tirzepatide). A trial in adults with obesity doesn't automatically create an indication for everyone with prediabetes. Our explainer on Mounjaro vs Ozempic walks through how these brand names line up.

What to discuss with a clinician

• How is my blood sugar being assessed, and how often should we recheck it?
• Based on my risk factors and local guidance, is medication appropriate for me, or are other steps the better fit?
• What lifestyle or diabetes-prevention programs are available to me?

Bring information about family history, previous glucose or A1C results and your current medicines. If you already take diabetes medicines, don't change them without advice.

Be careful with "reversal" headlines

Blood-sugar values can improve, and some people no longer meet the lab threshold for prediabetes after treatment and weight change. That's worth celebrating, but it doesn't mean the underlying risk has disappeared for good, as the off-treatment numbers above suggest. Ongoing monitoring still matters. If you're curious what long-term results look like after stopping, see what happens when you stop semaglutide.

The encouraging story is that metabolic risk can change. The responsible story is that your plan should be based on your clinical risk and current evidence, not a generic promise of prevention.