Short answer: No GLP-1 medicine is approved for type 1 diabetes. The diabetes labels cover type 2 only, and the Wegovy label says use in type 1 has not been evaluated. In two large trials adding liraglutide to insulin in type 1, A1C fell 0.2 to 0.3 points more than placebo and weight fell, but symptomatic lows and high sugar with ketones were more common.
Ozempic, Victoza, Trulicity, Mounjaro, Rybelsus and Byetta are each approved, along with diet and exercise, to improve blood sugar in type 2 diabetes (section 1). None lists type 1. The weight labels are written around obesity, and the Wegovy label says the use of Wegovy in patients with type 1 diabetes, or together with insulin, has not been evaluated (section 5.4).
Using a GLP-1 in type 1 is therefore off-label, a call for the prescriber. See off-label use.
Novo Nordisk tested liraglutide, the medicine in Victoza and Saxenda, added to insulin in adults with type 1 diabetes:
| Trial | People and length | A1C | Weight | Safety |
|---|---|---|---|---|
| ADJUNCT ONE (Mathieu 2016) | 1,398 adults, 52 weeks, insulin adjusted to target | 0.20 points lower than placebo | 4.9 kg lower | Symptomatic lows 31% more frequent; high sugar with ketosis about twice as frequent |
| ADJUNCT TWO (Ahrén 2016) | 835 adults, 26 weeks, insulin dose capped | -0.33 vs +0.01 on placebo | -5.1 vs -0.2 kg | More high sugar with ketosis (0.5 vs 0.1 events per person per year) |
ADJUNCT ONE adjusted insulin to reach glucose targets, while ADJUNCT TWO held insulin at a capped dose, so the two looked at the effect from different angles. Mean A1C at the start was 8.2% and 8.1%. Total insulin doses also went down. The ADJUNCT ONE authors wrote that the rise in lows and ketosis limits clinical use in type 1.
People with type 1 diabetes make little or no insulin, so their insulin dose has to match food. GLP-1 medicines slow the stomach and cut appetite, which can leave mealtime insulin without the food it was dosed for, and labels warn that GLP-1 medicines with insulin raise the risk of low blood sugar. If insulin is cut too far to avoid lows, ketones can build up, which can lead to diabetic ketoacidosis.
Someone with type 1 diabetes who is considering a GLP-1, often for weight, can ask how insulin doses would change, how often to check glucose and ketones, and what to do on days with vomiting or little food. A continuous glucose monitor may be part of the plan. Dose Track can log each GLP-1 injection alongside insulin doses and glucose notes, so the effect of each change is easy to review.
Read more on Dose Track: GLP-1 receptor agonist · Diabetic ketoacidosis · Hypoglycemia · Ozempic dosing guide