GLP-1 and dual-agonist medications were originally approved either for managing existing type 2 diabetes or, separately, for chronic weight management. A growing body of trial data now points to another effect worth understanding on its own terms: in people with prediabetes, these drugs appear able to return blood sugar to a normal range and substantially delay or prevent progression to full type 2 diabetes.

What SURMOUNT-1 Found

The clearest data on this point comes from a post hoc analysis of SURMOUNT-1, the pivotal Phase 3 trial for tirzepatide (marketed as Zepbound for weight management), which was discussed in more detail elsewhere on this site. Among the roughly 1,032 trial participants who had prediabetes at the start of the study, 94% of those treated with tirzepatide saw their blood glucose return to a normal range by the end of the study, and nearly 99% of tirzepatide recipients avoided progressing to type 2 diabetes altogether. Only 9 of 762 participants on tirzepatide developed type 2 diabetes over the trial's 176-week follow-up period, roughly three and a half years. Participants also saw weight reductions in the range of 12% to 23%, along with improvements in HDL cholesterol, waist circumference, blood pressure, and triglycerides.

An Important Caveat

This is a post hoc, or after-the-fact, analysis of a subgroup within a trial that was originally designed and powered to study weight management, not a dedicated diabetes-prevention trial with that outcome as its primary endpoint. That distinction matters for interpreting the strength of the evidence, discussed in more general terms elsewhere on this site: post hoc subgroup findings are a meaningful and encouraging signal, but they carry less certainty than a trial purpose-built around that specific question would. It's also worth being precise about regulatory status: tirzepatide's current FDA approvals cover treatment of type 2 diabetes and chronic weight management, not a distinct "diabetes prevention" indication, so this remains an area of active research rather than an approved use in its own right.

What About Semaglutide?

Semaglutide trials, including the STEP and SELECT programs covered elsewhere on this site, have similarly enrolled participants with prediabetes as part of broader weight-management and cardiovascular-outcome studies, and smaller analyses of that data have pointed in a similar directional pattern of improved glycemic measures. The most detailed, large-scale numbers currently available specifically on reversal of prediabetes and prevention of progression to type 2 diabetes come from the tirzepatide data described above, and readers should be cautious about assuming identical magnitude of effect across every drug in the GLP-1 and dual-agonist class until head-to-head or dedicated trial data confirms it.

How These Drugs Might Produce This Effect

Part of the benefit almost certainly flows from weight loss itself: excess body weight, particularly visceral fat, is a major driver of insulin resistance, and substantial weight loss on its own tends to improve blood sugar control regardless of how it's achieved. But GLP-1 and GIP receptor agonists also act directly on insulin secretion and glucagon suppression in ways that appear to contribute an effect beyond weight loss alone, which is part of why researchers are interested in these drugs specifically, rather than treating weight loss as the whole story.

What's Still Unknown

A significant open question is durability: whether the glycemic benefit persists after someone stops the medication, or whether, similar to the weight regain commonly observed after discontinuation, blood sugar control also tends to worsen once treatment ends. Long-term data addressing that specific question is still limited. It's also worth remembering that lifestyle intervention, the approach behind the long-running Diabetes Prevention Program studies, remains a well-established, lower-cost way to reduce progression from prediabetes to type 2 diabetes, and isn't rendered obsolete by these newer pharmacological findings.

The Bottom Line

The evidence that GLP-1 and dual-agonist medications can meaningfully improve blood sugar in people with prediabetes is genuinely strong and growing, but it comes with real caveats around study design, regulatory status, and long-term durability. Prediabetes management, including whether medication is appropriate, is a decision that should be made with a physician who can weigh someone's individual risk factors, rather than based on trial headlines alone.