Industry funded (moderate): Industry funding reported

No power calculation reported (low): No power calculation reported

Total daily insulin dose fell quickly and stayed lower through 26 weeks with semaglutide. The semaglutide group showed a 22.6% reduction from baseline by week 26, while the placebo group did not show the same pattern.

Bolus insulin fell more than basal insulin at every measured time point. By week 26, bolus insulin dose was down 30.5% from baseline, suggesting meal-related insulin needs dropped substantially with semaglutide.

Basal insulin dose also declined after semaglutide initiation, although the reduction was smaller than for bolus insulin. At week 26, basal insulin was 15.6% lower than baseline in the semaglutide group.

The parent trial reported an adjusted between-group weight reduction of 8.8 kg by week 26 with semaglutide versus placebo. Mediation analysis in this post hoc study suggested weight loss explained more of the insulin-dose reduction later in treatment.

The paper cites parent trial findings showing an 8.8% higher time in range at week 26 with semaglutide versus placebo. Because this post hoc analysis focused on insulin dosing rather than reanalyzing CGM efficacy as a primary aim, the strength is best treated as supportive rather than central here.

The article references the parent trial result showing a 0.3% adjusted reduction in HbA1c with semaglutide versus placebo at week 26. This outcome was not the main focus of the post hoc analysis, so it is best interpreted as a modest supporting benefit.

The paper states that severe hypoglycemia events were similar between semaglutide and placebo groups. That suggests semaglutide did not clearly worsen this safety outcome within the trial setting.

No diabetic ketoacidosis events were reported during the study. One high-ketone event that did not meet diabetic ketoacidosis criteria and one hyperglycemia event due to infusion-site failure were reported in the semaglutide group.

Once-weekly semaglutide titrated from 0.25 mg to 0.5 mg and then up to 1 mg over 26 weeks as adjunct therapy to insulin in adults with type 1 diabetes and obesity using automated insulin delivery.

Positive: 6; Negative: 0; No effect: 2; Mixed: 0

Extracted 8 outcome signals across the study

Most extracted outcomes favored semaglutide, especially insulin dose reduction, weight loss, and time in range, while major safety signals were not clearly increased in this trial.

Total daily insulin dose ↓ by 22.6% at 26 weeks with semaglutide

Bolus insulin dose ↓ more than basal insulin dose over time

Mostly intermediate or surrogate outcomes

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.

Karakus KE, Akturk HK, Kruger D, et al. Effect of Semaglutide on Insulin Dose Reduction in Adults With Type 1 Diabetes and Obesity Using Automated Insulin Delivery Systems: ADJUST-T1D Post Hoc Analysis. Diabetes Care. 2026;49(5):718-723. doi:10.2337/dc25-2249

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.

In adults with type 1 diabetes, obesity, and automated insulin delivery, semaglutide lowered total, bolus, and basal insulin needs over 26 weeks while early dose reductions were only partly explained by weight loss.

Body weight ↓ and time in range ↑ in the parent trial results

Severe hypoglycemia ↔ and diabetic ketoacidosis events were not reported

This guideline reviews physical activity, exercise safety, and glucose management in diabetes. It helps place insulin adjustment and device-supported glucose monitoring into broader clinical guidance for people living with type 1 diabetes.

ADA Standards of Care in Diabetes - 2025: Physical Activity

This is the parent ADJUST-T1D randomized trial that established the main efficacy and safety findings for semaglutide in adults with type 1 diabetes and obesity. It provides the core trial context that this insulin-dose post hoc analysis builds on.

Semaglutide in adults with type 1 diabetes and obesity

This randomized crossover trial tested semaglutide with automated insulin delivery in type 1 diabetes and offers closely related evidence on glycemic benefits, weight change, and insulin dosing. It strengthens the broader evidence base for adjunct semaglutide in this setting.

Subcutaneous weekly semaglutide with automated insulin delivery in type 1 diabetes: a double-blind, randomized, crossover trial

Limited population scope (moderate): Narrow population scope

Limited safety reporting (moderate): Safety reporting depth: limited

No post-intervention follow-up (moderate): 0 weeks of follow-up after treatment ended

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

This study looked at how semaglutide changed insulin needs in adults with type 1 diabetes and obesity who used automated insulin delivery. Over 26 weeks, semaglutide lowered total insulin needs, especially bolus insulin, while also improving weight and glucose time in range without a clear rise in severe hypoglycemia.

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.

Semaglutide effects on insulin dosing, weight loss, and glucose outcomes in adults with type 1 diabetes and obesity

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.

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

American Diabetes Association

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