More people with type 1 diabetes are using GLP-1 drugs, study finds, despite limited evidence on safety or effectiveness

CNN

09-04-2025

The use of drugs like Ozempic, Wegovy and Zepbound in people with type 1 diabetes has risen sharply over the past decade, a new study finds, even though there's little information on the drugs' safety and effectiveness for the condition.
The family of medications called GLP-1 receptor agonists includes drugs like Wegovy, Zepbound, Ozempic, Mounjaro and Victoza. They were originally developed to treat type 2 diabetes, which happens when the body's cells become resistant to the hormone insulin. Some of them have also been found to be safe and effective to help with weight loss, to treat sleep apnea and to reduce the risk of heart attacks and strokes in people who don't have diabetes.
But the clinical trials of these medications specifically excluded people with type 1 diabetes, who are dependent on the hormone insulin to survive because they can't make enough of their own. Drugmakers feared that using the GLP-1 medications with insulin might raise the chance of dangerously low blood sugar events, or hypoglycemia, and were unwilling to take the risk of studying them in people with type 1.
The medication labels for Ozempic and Mounjaro, which are prescribed to help people with type 2 diabetes manage blood sugar, specifically say they are not intended for use with type 1.
However, despite the lack of evidence, many doctors began prescribing GLP-1 medications off-label for their type 1 patients, especially those who also have obesity.
The new study reflects this growing practice.
For the study, which was published last month in the journal Diabetes, Obesity, and Metabolism, researchers at Johns Hopkins University reviewed the medical records of more than 200,000 people with type 1 diabetes from 2008 to 2023.
They grouped the data in three-year periods, starting with October 2008 to September 2011 and ending with October 2020 to September 2023.
Over these periods, obesity rates increased substantially among people with type 1 diabetes. Among children ages 2 to 19, obesity rates climbed from 18% to 26%, and they rose from 30% to 38% among adults 20 and older.
GLP-1 medication use spiked, as well. Among adults with the highest category of obesity, about 4% used GLP-1 medications in 2008, and 33% did by 2023 – an 800% increase.
Some people with type 1 say these drugs have been game-changers, helping them gain control of wild blood sugar swings for the first time. They can also help type 1 diabetes patients lose weight, something that's especially difficult for people who take insulin, which signals the body to take extra sugar out of the blood and store it as fat.
But these are anecdotal reports and may not reflect instances in which people have side effects or complications like low blood sugar, which can be life-threatening.
'We really need the clinical trial data dedicated for this type 1 diabetes population and see whether this is effective and safe in this population,' said study author Dr. Jung-Im Shin, an epidemiologist at the Johns Hopkins Bloomberg School of Public Health.
Smaller retrospective studies – those that look back in time – suggest that there are benefits to using GLP-1 medications with type 1 diabetes.
But Shin says what's really needed is information from randomized, double-blinded studies, in which participants are followed forward in time and given either a drug or a placebo.
Some of that data is coming soon, says Dr. Viral Shah, an endocrinologist and director of diabetes clinical research at the Indiana University School of Medicine who was not involved in the new study.
Shah says that, like many of his colleagues, he prescribes GLP-1 medications for certain type 1 patients.
'Most endocrinologists nowadays do understand that people with type 1 diabetes – not everyone, but some, would benefit' from a second medication along with their insulin. In addition to GLP-1 medications, a class of medications used in type 2 diabetes called SGLT-2 inhibitors is also being studied for use with type 1 diabetes.
GLP-1 drugs can help lower the amount of insulin a person requires to control their blood sugar and may help people who have type 1 and obesity to lose weight.
Because of the risk of low blood sugar, Shah says, it's really important to work with a doctor on dosing of both the GLP-1 and insulin.
Shah says he would caution people with type 1 who are not overweight to avoid taking a GLP-1 drug, since retrospective studies have found that this group tends to have more gastrointestinal side effects, which may lead them to stop using the drug.
Several ongoing studies are looking at the use of GLP-1 medications in type 1 diabetes, Shah says, including one he led, which will be presented in at the American Diabetes Association's annual meeting in June.
Shah's study, which included people who had type 1 and obesity, was a randomized, double-blinded study in patients who use an artificial pancreas to control their blood sugar. An artificial pancreas is a system that uses a computer to deliver insulin based on real-time blood sugar readings.
Half of the participants got a weekly shot of semaglutide, the drug in Ozempic and Wegovy, while the other half got a placebo injection. The participants were followed for a total of six months.
A similar trial under way at Yale University will follow patients for a year, with data expected in 2028.