Tirzepatide Shows Promise for Weight Loss and Better Blood Sugar Control in Type 1 Diabetes

A new study finds that tirzepatide, a medication originally developed for type 2 diabetes and weight management, was associated with significant weight loss and reduced insulin needs in people with type 1 diabetes who are overweight or obese. The findings suggest potential benefits, though more research is needed.

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Key takeaways

Adults with type 1 diabetes taking tirzepatide lost an average of 10% of their body weight over about 28 weeks, while the control group gained weight.
Tirzepatide was associated with a reduction in daily insulin requirements of about 22 units per day, compared to an increase in the control group.
Continuous glucose monitoring data showed improvements in several measures, including lower glucose variability and a reduced glucose management indicator.
This was a small study of 23 matched pairs, so larger clinical trials are needed to confirm these results and establish safety in type 1 diabetes.

What This Study Looked At

Researchers at Royal North Shore Hospital and the Northern Sydney Endocrine Centre compared 23 adults with type 1 diabetes who took tirzepatide to 23 matched control participants who did not. All participants had a BMI of 27 or higher (overweight or obese) and used continuous glucose monitors. The study was conducted between 2020 and 2025, and participants were followed for about 28 to 31 weeks.

Key Findings on Weight and Insulin Use

The tirzepatide group experienced a 10% average reduction in body weight, while the control group's weight remained relatively stable. More notably, people taking tirzepatide reduced their total daily insulin dose by an average of about 22 units per day. In contrast, the control group's insulin requirements increased slightly.

The most commonly prescribed dose of tirzepatide in this study was 5 mg per week.

Effects on Blood Sugar Control

Beyond weight loss, tirzepatide was associated with improvements in several continuous glucose monitoring metrics. These included a lower glucose management indicator—a measure that reflects overall glucose control—and reduced glucose variability, meaning blood sugars swung less dramatically throughout the day.

Participants in the tirzepatide group also reported consuming fewer carbohydrates on average compared to their baseline.

Important Limitations

This was a small, retrospective study conducted at two centers in Australia. Retrospective studies rely on medical records rather than data collected specifically for research, which can introduce bias. The sample size of 23 paired participants is relatively small.

The study does not establish tirzepatide as a standard treatment for type 1 diabetes. Larger, prospective randomized controlled trials are needed to confirm these findings, assess long-term safety and efficacy, and determine which people with type 1 diabetes might benefit most from this approach.

What It Means for You

These results suggest tirzepatide may help some people with type 1 diabetes who struggle with weight management and insulin sensitivity achieve weight loss and potentially lower their insulin requirements. However, tirzepatide is not currently approved by regulatory agencies specifically for type 1 diabetes.

If you are interested in learning whether tirzepatide might be appropriate for your situation, discuss it with your endocrinologist. They can evaluate your individual health status and help determine whether further evaluation is warranted.

Evidence label

Source: Diabetes, obesity & metabolism. Evidence type: PubMed indexed literature. Type1Cure is an information and intelligence hub, not a medical advice service. This article summarizes published research and does not provide diagnosis, treatment, or personal medical guidance. Always talk to your own care team before changing anything about your Type 1 diabetes management.

Type1Cure is an information and intelligence hub, not a medical advice service. This article summarizes published research and does not provide diagnosis, treatment, or personal medical guidance. Always talk to your own care team before changing anything about your Type 1 diabetes management.

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