A clinical trial funded by Breakthrough T1D will investigate whether tirzepatide, a medication currently used to help adults manage type 2 diabetes, could also be safe and beneficial for people living with type 1 diabetes (T1D).
The Challenge
Despite major advances in diabetes technology and treatment, managing type 1 diabetes remains a daily challenge. Blood glucose levels can be influenced by far more than food and drink, with factors such as stress, sleep, exercise and even weather conditions playing a role.
As a result, many people living with T1D struggle to keep their blood glucose levels within a healthy target range. Over time, repeated periods of high blood glucose can damage organs including the kidneys, heart and eyes, leading to serious long-term complications. At the same time, episodes of very low blood glucose can be dangerous and, in some cases, fatal.
Overall, there is a significant unmet need for treatments that reduce blood glucose levels without causing extreme hypoglycaemia (low blood glucose).
The Research
The TIRTLE2 clinical trial, which is being led by Dr Jennifer Snaith at the Victor Chang Cardiac Research Institute will enrol 44 adults living with T1D who are carrying excess weight. Participants will receive a weekly injection of either tirzepatide or a placebo alongside their usual insulin therapy for six weeks.
The research team will examine how tirzepatide affects:
- Insulin sensitivity
- Glucagon responses during low blood glucose
- Hormonal responses to meals and overnight
- Insulin requirements
- Time spent within target blood glucose range
- Blood vessel stiffness
- Energy expenditure
- Stomach emptying
Potential Impact
This study aims to provide important proof-of-concept data on the safety and effectiveness of tirzepatide in people living with T1D. Researchers hope the findings will reveal whether tirzepatide can help improve glucose regulation and reduce the amount of insulin required by people with T1D.
Ultimately, this research represents an important first step towards expanding treatment options beyond insulin alone, with the goal of making T1D management safer, easier and more effective.
Funding support from Hearts and Minds Investments. For further information and updates, visit Breakthrough T1D. This content was last updated in 2026.
