Benefits of GLP-1s for Type 1 Diabetes and Obesity
Life-changing medications like Ozempic and Mounjaro are only approved right now for type 2 diabetes, but a growing body of evidence highlights the benefits of GLP-1s for people with type 1 diabetes.
Semaglutide (Ozempic, Wegovy) is a GLP-1 receptor agonist, and tirzepatide (Mounjaro, Zepbound) is a dual GIP/GLP-1 receptor agonist. Both medicines are used for blood sugar and weight management in people with type 2 diabetes and excess weight or obesity.
Several studies have shown that use of GLP-1 medications in people with type 1 diabetes and overweight or obesity results in significant weight loss as well as marked improvements in A1C, time in range, and risk factors for heart and kidney disease. Larger trials are underway to confirm these early successes.
What the research says about GLP-1s for type 1
Researchers recently examined U.S. medical records to get a sense of how GLP-1 use among people with type 1 diabetes has changed over time and shared their results at the 2026 ATTD conference. GLP-1 medications are not yet approved for those with type 1 diabetes due to concerns around diabetic ketoacidosis (DKA) and hypoglycemia, but many people use them off-label for blood sugar and weight management.
Newer studies have found that the number of people with type 1 diabetes taking GLP-1s has grown exponentially in the years since, particularly among adults between the ages of 18 and 85, but use has also grown among children and older adults. Research has found that people with type 1 who started on GLP-1s like Ozempic or Mounjaro have achieved modest reductions in A1C values and significant reductions in body weight.
Now, researchers are analyzing the data to see how GLP-1 drugs affect the risk of heart, kidney, and liver disease for people with type 1 diabetes. Focusing specifically on Mounjaro, a 2025 study in adults with type 1 diabetes and overweight or obesity found that after 21 months, participants experienced 23% weight loss, sustained improvements in glucose management, and significant improvements in blood pressure, cholesterol, triglycerides, and eGFR (a marker of kidney function). They also saw roughly a 16-fold decrease in the amount of total daily insulin needed.
“Such a huge decrease in insulin doses puts people at risk of DKA and hypoglycemia, but none of them were reported, at least in this cohort,” said Dr. Satish Garg, a professor at the Barbara Davis Center for Diabetes and lead author on the study.
Garg said the main reason people discontinued in the tirzepatide study was due to cost (they either could no longer afford the drug or their insurance stopped covering it).
Small trials pave the way for larger studies
Two studies published in 2025 showed that semaglutide can help people who manage type 1 diabetes with automatic insulin delivery (AID) systems. The first was primarily focused on the effects of the drug on glucose management. It lasted about four months and included 28 adults with type 1 diabetes. The participants who used semaglutide spent more time in range and did not have increased time below range.
In the second study, researchers also considered the effectiveness of semaglutide for weight management. They recruited 72 adults who had both type 1 diabetes and obesity. During the trial, which lasted just under seven months, 36% of participants taking semaglutide spent more than 70% of their time in range, less than 4% of their time below range, and lost more than 5% of their body weight compared to those not taking the drug.
After the trial concluded, researchers also checked to see how the participants' heart health had changed and shared the results of that analysis at the 2026 ATTD conference. Treatment with semaglutide was also associated with reductions in cholesterol and blood pressure. Based on all of these changes, the researchers calculated that the participants who received semaglutide had significantly reduced their risk of heart disease over the next 10 years.
Meanwhile, another 2025 study demonstrated the safety and effectiveness of tirzepatide in 24 adults with type 1 diabetes and obesity. Over the 12-week study, participants lost an average of about 20 pounds, and most of that weight loss (82%) was fat mass – not lean muscle. In addition, people in the study reduced their insulin use by an average of 35%, and their A1C dropped by 0.35%. No severe hypoglycemia or DKA was reported.
Early data are promising, but results from larger clinical trials are still needed to confirm the long-term benefits in this population. That's why Eli Lilly launched a trial in 2025 to assess the safety and effectiveness of tirzepatide in adults with type 1 diabetes and obesity or overweight.
The bottom line
Continuing to study the safety and efficacy of GLP-1 drugs for people with type 1 diabetes is crucial. These medications have only been officially approved for people with type 2 diabetes, but research continues to show that they can benefit people with type 1 as well.
“Whether it’s type 1 or type 2 diabetes, both groups have a higher risk of developing heart and kidney disease. If these drugs are known to prevent both of those complications, it makes sense to use these drugs irrespective of which type of diabetes you have,” Garg said.
People with type 1 diabetes are already using GLP-1 medications, but larger studies verifying that these drugs are safe for weight loss and glucose management in this group are necessary. To make an official approval possible, we need more concrete evidence of the unique risks and benefits GLP-1 drugs offer to people with type 1 diabetes.
Learn more about treatments for type 1 diabetes here: