Tirzepatide Dramatically Reduced the Risk of Developing Type 2 Diabetes in People With Obesity | Research

The takeaway

A systematic review found tirzepatide reduced the risk of developing type 2 diabetes by 88-93% versus placebo over 3-4 years, and by 27% compared to semaglutide at one year, in people with obesity or overweight.

93% diabetes risk reduction
Tirzepatide reduced the hazard of developing type 2 diabetes by 93% compared to placebo at 176 weeks in people with obesity (HR=0.07)

What the researchers found

Three eligible studies (one RCT and two cohort studies) provided data on tirzepatide's diabetes prevention effects:

Tirzepatide vs. placebo:

- At 176 weeks (~3.4 years): HR = 0.07 (95% CI: <0.01-0.1; P<0.001) — a 93% risk reduction

- At 193 weeks (~3.7 years): HR = 0.12 (95% CI: 0.1-0.2; P<0.001) — an 88% risk reduction

Tirzepatide vs. semaglutide:

- At 12 months: HR = 0.73 (95% CI: 0.58-0.92; P<0.001) — a 27% risk reduction

All comparisons were statistically significant. The hazard ratios against placebo are particularly dramatic, suggesting tirzepatide nearly eliminates the risk of diabetes progression in the treatment period.

Why it matters

About 96 million American adults have prediabetes, and up to 70% of them will eventually develop type 2 diabetes. Preventing that transition — rather than treating diabetes after it develops — could fundamentally change the trajectory of one of the world's most prevalent chronic diseases. A 93% risk reduction with tirzepatide suggests that for many people, type 2 diabetes could become a preventable disease rather than an inevitable consequence of obesity.

How the study worked

This was a systematic review following PRISMA guidelines, registered on PROSPERO (CRD42024614466). Six databases (PubMed, ClinicalTrials.gov, EMBASE, Scopus, Web of Science, Cochrane Library) were searched through July 10, 2025. Two-stage dual screening with third-person adjudication was used. Study quality was assessed using RoB 2.0 for RCTs and Newcastle-Ottawa Scale for cohort studies. Three studies were eligible: one randomized controlled trial and two cohort studies. Hazard ratios for new-onset diabetes were the primary outcome.

What this study cannot tell us

Only three studies met inclusion criteria, and only one was a randomized controlled trial — the other two were cohort studies with inherent confounding risks. The diabetes prevention findings come from secondary or post hoc analyses of trials primarily designed for other endpoints (weight loss, metabolic improvement). The very low hazard ratios (0.07, 0.12) should be interpreted cautiously given the small number of studies. Cost, insurance coverage, and treatment durability after discontinuation are not addressed. Long-term data beyond 4 years is not available.

How to read the evidence

This is a systematic review of three studies (one RCT, two cohort studies), providing moderate-level evidence. The systematic methodology (PROSPERO-registered, multi-database search, quality assessment) adds rigor, but the small number of included studies and the secondary-endpoint nature of the diabetes prevention findings limit the evidence strength. Dedicated RCTs for diabetes prevention are needed.

When this study was published

Published in 2026, this systematic review includes data through mid-2025 and represents the latest synthesis of tirzepatide's diabetes prevention potential.

The bigger picture

Diabetes prevention has been a goal of medicine for decades — lifestyle interventions (diet and exercise) can reduce risk by about 58%, and metformin by about 31%. Tirzepatide's 88-93% risk reduction represents a quantum leap. As a dual GLP-1/GIP receptor agonist, tirzepatide outperforms single-target GLP-1 drugs like semaglutide in both weight loss and metabolic improvement. If confirmed in dedicated prevention trials, tirzepatide could justify a paradigm shift toward treating prediabetes as aggressively as hypertension or high cholesterol.

Questions still open

Will tirzepatide's diabetes prevention effect persist after the drug is discontinued, or will risk return when treatment stops?
Is the cost of long-term tirzepatide treatment justified by diabetes prevention, given the lifetime costs of managing type 2 diabetes?
Should tirzepatide be approved specifically for diabetes prevention in high-risk individuals, or is lifestyle intervention still the preferred first step?

Common questions

How is tirzepatide different from other diabetes prevention approaches?

Traditional diabetes prevention relies on lifestyle changes (diet and exercise, ~58% risk reduction) or metformin (~31% risk reduction). Tirzepatide's 88-93% risk reduction is dramatically better. As a dual GLP-1/GIP receptor agonist, tirzepatide targets two gut hormone pathways simultaneously, producing more weight loss and better metabolic improvement than older drugs. However, it requires weekly injections and is expensive, so it would likely be used alongside — not instead of — lifestyle changes.

Does tirzepatide actually cure prediabetes, or just delay diabetes while you take it?

This is a critical unanswered question. The review shows tirzepatide prevents diabetes during treatment, but it's unclear what happens when patients stop taking it. If the weight lost during treatment is maintained, some of the metabolic benefits may persist. But if weight is regained — which often happens when GLP-1/GIP drugs are discontinued — diabetes risk would likely return. Long-term studies following patients after treatment discontinuation are needed to answer this definitively.

Read the original research

Effect of Tirzepatide on the Risk of Developing Type 2 Diabetes Mellitus Among the People Living With Obesity or Overweight: A Systematic Review.

Clinical obesity, 16(1), e70042

View on PubMed ↗Publisher’s paper ↗

Citation

Pardeshi, Geeta; Kumbhar, Uddhav T; Kaviprawin, Mogan; Debnath, Aninda; Dubey, Ashok Kumar; Deshmukh, Kalyani; Goyal, Chanchal; Gandhi, Aravind P. (2026). Effect of Tirzepatide on the Risk of Developing Type 2 Diabetes Mellitus Among the People Living With Obesity or Overweight: A Systematic Review.. Clinical obesity, 16(1), e70042. https://doi.org/10.1111/cob.70042