Semaglutide cuts insulin needs in adults with type 1 diabetes and obesity

• Semaglutide reduced total daily insulin dose by 17.7% at week 4 and 22.6% at week 26 from baseline.
• Bolus insulin fell by 30.5% at week 26, which was a larger reduction than the 15.6% drop in basal insulin.
• Mediation analysis suggested 83% of the week 4 insulin reduction reflected a direct drug effect, while weight loss explained 48% of the difference by week 26.
• The parent ADJUST-T1D trial also reported improved time in range, lower HbA1c, and weight reduction versus placebo.

These findings apply most directly to adults aged 18 to 65 with type 1 diabetes, obesity, and access to FDA-approved automated insulin delivery systems. They may be most relevant to people considering adjunct semaglutide while already receiving structured insulin management and continuous glucose monitoring.

This paper focused on insulin-dose patterns within a randomized trial and was not designed as a broad real-world effectiveness study. The participants had obesity and used automated insulin delivery, so the findings may not translate to people without obesity, those using injections alone, or settings without close follow-up. Because the analysis was post hoc, the results are best used to guide careful dose adjustment rather than as a stand-alone practice rule.

• This was a post hoc analysis rather than the original primary trial analysis.
• Only 72 participants were randomized, which limits precision.
• Carbohydrate entry data were missing for about one-third of participants.
• The trial used semaglutide up to 1 mg, so the results may not apply to higher doses.