Century Old Metformin Lowers Insulin Dependency by Twelve Percent in New Type 1 Diabetes Trial

A new trial shows metformin helps type 1 diabetes patients use 12% less insulin. Discover how this cheap drug is changing autoimmune care through the gut.

By: AXL Media

Published: Apr 16, 2026, 10:59 AM EDT

Source: Information for this report was sourced from ScienceDaily

Repurposing a Common Medication for Autoimmune Management

A significant breakthrough in the treatment of type 1 diabetes has emerged from a clinical study exploring the secondary benefits of metformin, a drug typically reserved for type 2 diabetes. Led by the Garvan Institute of Medical Research, the study found that this inexpensive, century old medication can help patients manage their condition with less synthetic insulin. While type 1 diabetes is an autoimmune disease requiring lifelong insulin therapy, the integration of metformin appears to offer a supportive role that was previously unconfirmed by rigorous clinical data. This discovery is particularly relevant for the more than 130,000 Australians living with the condition, many of whom face the constant burden of making hundreds of daily health decisions to maintain safe blood sugar levels.

A Rigorous Assessment of Insulin Resistance Claims

For years, some medical professionals have prescribed metformin off label to type 1 patients under the assumption that it would combat insulin resistance. To test this theory, researchers conducted the Insulin Resistance in Type 1 Diabetes Managed with Metformin study, involving 40 adults with long term diagnoses. According to Professor Jerry Greenfield, the team utilized a sophisticated research technique known as a clamp study to map how insulin was processed in various parts of the body over a six month period. Contrary to their initial expectations, the results indicated that metformin did not actually improve the body's sensitivity to insulin. Participants did not show significant changes in their underlying resistance levels, nor were there major shifts in overall blood sugar averages compared to the placebo group.

The Discovery of Reduced Dosage Requirements

Despite the lack of impact on insulin resistance, the trial yielded a surprising and clinically significant secondary outcome regarding total insulin volume. Participants who were administered metformin required approximately 12% less insulin to keep their blood sugar within a healthy range than those in the control group. According to Dr. Jennifer Snaith, an endocrinologist and co lead of the study, lowering the amount of required insulin is a high priority for many patients due to the physical and mental toll of the therapy. Even without altering the body's sensitivity to the hormone, the drug pr...