Semaglutide and Tirzepatide for Type 1 Diabetes: Can GLP-1 Drugs Help Beyond Type 2? | Research

The takeaway

Growing real-world evidence suggests semaglutide and tirzepatide may benefit type 1 diabetes patients as add-ons to insulin — improving glucose control, weight, and potentially preserving remaining insulin-producing cells.

Not yet approved
Neither semaglutide nor tirzepatide is currently FDA-approved for type 1 diabetes, but off-label use is growing as real-world evidence accumulates showing benefits

What the researchers found

Semaglutide and tirzepatide — originally developed for type 2 diabetes and obesity — show promise as add-on treatments to insulin in type 1 diabetes (T1D), double diabetes, and latent autoimmune diabetes in adults (LADA). Evidence from mostly real-world studies suggests these GLP-1-based drugs improve glucose control, promote weight loss, may preserve remaining beta-cell function, and provide additional metabolic benefits in T1D patients.

The concept of 'double diabetes' — T1D patients who also develop insulin resistance, obesity, or metabolic syndrome — is emerging as a significant clinical challenge. Neither semaglutide nor tirzepatide is currently approved for T1D, but off-label use is growing as overweight and obesity increasingly affect T1D populations.

Why it matters

Type 1 diabetes treatment has been stuck on insulin-only therapy for a century. As T1D patients increasingly struggle with the same obesity and metabolic problems as the general population, the potential to add GLP-1 drugs to their treatment could be transformative — reducing insulin doses, controlling weight, and potentially slowing the autoimmune destruction of remaining beta cells. This represents a paradigm shift in how T1D might be managed.

The numbers in context

Not approved for T1D · growing real-world evidence · targets T1D + double diabetes + LADA populations

How the study worked

Comprehensive review of available literature — primarily real-world studies, case reports, and small clinical trials — on the safety and efficacy of semaglutide and tirzepatide used in type 1 diabetes, double diabetes, and LADA patients.

Who was studied

Patients with type 1 diabetes, double diabetes (T1D with obesity/insulin resistance), and latent autoimmune diabetes in adults (LADA)

What this study cannot tell us

The evidence base is mostly real-world studies and case reports rather than large randomized controlled trials. Neither drug is approved for T1D, and off-label use introduces selection bias. Long-term safety in T1D patients — particularly regarding DKA risk and beta-cell preservation — needs more rigorous study. Hypoglycemia risk when combining GLP-1 drugs with insulin requires careful management.

How to read the evidence

This is a comprehensive review drawing mostly on real-world studies and case reports rather than randomized controlled trials. The evidence is promising but not yet definitive, and neither drug has regulatory approval for T1D.

When this study was published

Published in 2025 in the Journal of Clinical Medicine. Very current review capturing the latest evidence on an actively evolving topic in diabetes care.

The bigger picture

The GLP-1 revolution that transformed type 2 diabetes and obesity treatment is now expanding into type 1 diabetes territory. If larger clinical trials confirm the real-world findings, we could see the first major addition to T1D management beyond insulin in decades. The 'double diabetes' concept also challenges the traditional binary of T1D vs T2D, recognizing that metabolic syndrome can complicate autoimmune diabetes just as it does in the general population.

Questions still open

Will randomized controlled trials confirm the real-world benefits of GLP-1 drugs in type 1 diabetes?
Does GLP-1 receptor agonism genuinely preserve beta-cell function in T1D, or does it just reduce the metabolic load on remaining cells?
What is the risk of diabetic ketoacidosis when T1D patients reduce insulin doses while taking GLP-1 drugs?

Common questions

Can people with type 1 diabetes take Ozempic or Mounjaro?

These drugs are not approved for type 1 diabetes, but some doctors prescribe them off-label as add-ons to insulin. Early evidence suggests they can help with weight loss and blood sugar control in T1D patients, particularly those who are overweight. However, insulin cannot be stopped — T1D patients still need it, and dose adjustments require careful medical supervision.

What is 'double diabetes'?

Double diabetes describes people who have type 1 diabetes (autoimmune) but also develop insulin resistance, obesity, or metabolic syndrome — features typically associated with type 2 diabetes. This growing population may benefit most from adding GLP-1 drugs to their insulin regimen, as these medications address both the metabolic and weight components.

Read the original research

Unveiling the Therapeutic Potential of the Second-Generation Incretin Analogs Semaglutide and Tirzepatide in Type 1 Diabetes and Latent Autoimmune Diabetes in Adults.

Journal of clinical medicine, 14(4)

View on PubMed ↗Publisher’s paper ↗

Citation

Infante, Marco; Silvestri, Francesca; Padilla, Nathalia; Pacifici, Francesca; Pastore, Donatella; Pinheiro, Marcelo Maia; Caprio, Massimiliano; Tesauro, Manfredi; Fabbri, Andrea; Novelli, Giuseppe; Alejandro, Rodolfo; De Lorenzo, Antonino; Ricordi, Camillo; Della-Morte, David. (2025). Unveiling the Therapeutic Potential of the Second-Generation Incretin Analogs Semaglutide and Tirzepatide in Type 1 Diabetes and Latent Autoimmune Diabetes in Adults.. Journal of clinical medicine, 14(4). https://doi.org/10.3390/jcm14041303