Weight-loss medications like Ozempic, Mounjaro, and other glucagon-like peptide-1 receptor agonists (GLP-1s) have exploded in popularity in recent years, with nearly 15 million Americans having tried one at some point. But there’s one group of people taking the powerful medications that has doctors concerned: those with type 1 diabetes.
Both adults and children with type 1 diabetes are taking GLP-1s more than they used to, according to a study published in March. The authors attribute the demand to rising obesity rates among people with type 1 diabetes, from 30% in 2008 to 38% in 2023.
The Food and Drug Administration has approved GLP-1s to manage type 2 diabetes, obesity, or both (and one, Wegovy, to reduce major cardiovascular events for some people). But none have been green-lit to treat type 1 diabetes, also sometimes referred to as T1D.
In fact, prior research suggests that for people with type 1 diabetes, the medications may have dangerous consequences.
“While these medications may offer benefits such as weight loss and cardiovascular protection—similar to those seen in people with type 2 diabetes or obesity—there are concerns about an increased risk of hypoglycemia,” or too low blood sugar, said senior study author Jung-Im Shin, MD, PhD, an associate professor of epidemiology at the Johns Hopkins Bloomberg School of Public Health.
A chronic condition, type 1 diabetes most often—but not always—develops in childhood and is the least common type, affecting up to 10% of people with diabetes.
The disease occurs when the pancreas doesn’t produce enough insulin, a hormone that helps the body have energy by moving sugar from the blood to the cells. Left untreated, too much sugar in the blood can have devastating consequences, damaging the heart, kidneys, nerves, eyes, and more.
Most people with type 1 diabetes have to take insulin shots or wear an insulin pump.
Unlike type 2 diabetes, type 1 diabetes has traditionally been linked with people who are thin or average weight.
However, obesity rates—especially among Black and Hispanic youth—have been steadily increasing among people with a type 1 diabetes diagnosis. For some people, intensive insulin treatment can contribute to weight gain. Others might overeat or not exercise enough in an attempt to avoid hypoglycemia, a common complication of the disease.
“The rise in obesity rates has led to an increased interest in the use of this class of drug for overweight and obese individuals with T1D,” Marina Basina, MD, a clinical endocrinologist with Stanford Medicine, told Health.
Between 2020 and 2023, roughly 17% of obese youth and almost 27% of obese adults with type 1 diabetes were prescribed GLP-1s, according to the new study. Over 60% of those with type 1 diabetes and GLP-1 prescriptions took liraglutide, semaglutide (the active ingredient in Ozempic and Wegovy), or tirzepatide, sold under the brand names Zepbound and Mounjaro.
According to Shin, GLP-1 drugs are designed to lower blood sugar levels by stimulating insulin production and suppressing secretion of the hormone glucagon, which raises blood sugar levels (and also slows digestion and curbs appetite).
The medications can offer benefits for people with type 2 diabetes, such as improving glycemic control, insulin activity, curbing post-meal blood sugar spikes, and protecting the heart and kidneys, Basina said. However, she noted that there hasn’t been enough research to determine whether GLP-1s affect people with type 1 diabetes in the same way.
Research has found only that liraglutide—taken once daily—improved glycemic control, weight loss, and insulin activity in people with type 1 diabetes. But researchers also discovered that it raised the risk of two conditions: hypoglycemia and hyperglycemia with ketosis, which is high blood glucose with the presence of high levels of ketones, a type of acid the body makes when it uses fat instead of glucose for energy.
Hypoglycemia can occur when a GLP-1 is used in combination with insulin. “The combined effect can lower blood sugar too much, which may lead to hypoglycemia,” Shin told Health. But when someone lowers their insulin dose while on a GLP-1, as some doctors may suggest, that could lead to the opposite problem—high blood sugar.
Shin said that it’s urgent that researchers investigate the health risks of taking GLP-1s in people with type 1 diabetes, especially because many are already taking them. Longer and larger prospective studies are needed to inform clinical guidance about how this population can safely use GLP-1s, Basina said.
In the meantime, it’s crucial for physicians—and patients with type 1 diabetes—to weigh the risks and benefits and monitor for side effects if they choose to take GLP-1s. “It’s important to let patients know that although the drugs have been very effective in the short term, the long-term data on the benefits and risks is not well established,” Basina said.
