A Once-a-Week Injectable Basal Insulin

Written August 2020, updated February 2023

People with type 1 diabetes (T1D) either use an insulin pump or multiple daily injections to take their insulin. Injection treatment requires using two types of insulin, and generally a total of four daily injections: 

  • One type of rapid-acting insulin, which is active for about four hours to cover the expected blood sugar spike following a meal. 
  • One type of long-acting insulin, which is generally taken once a day to cover basal insulin needs between meals.

Experts are mainly aiming to improve the different types of rapid-acting and long-acting insulin, making them increasingly rapid, or increasingly long-lasting and stable, in order to simplify diabetes management.   

Two pharmaceutical companies are currently conducting – more or less – advanced research to offer a once-a-week basal insulin. This is the case for Novonordisk’s Icodec insulin, whose research in people with type 2 diabetes are promising and whose approval may soon be requested from the FDA. Research are currently being conducted in people with T1D and is expected to be published in 2023.

How does it work?

Due to its two main mechanisms, insulin icodec takes longer to work and to be eliminated from the body:

  • Following the injection, its molecules break down very slowly, releasing the insulin in the bloodstream gradually.
  • Once in the bloodstream, insulin icodec forms a stronger bond with a protein called albumin than other types of basal insulin available, which allows it to stay in the body for several days. 

How does it compare to other types of basal insulin?

The study concluded that insulin icodec was as effective as insulin glargin (e.g., Basaglar, Lantus), and the researchers did not observe any significant improvement in hemoglobin A1c (HbA1c) for the group that used insulin icodec versus the group that used insulin glargin. The risk of hypoglycemia was similar in both groups. 

On average, about 229 units of icodec were required for one week, as opposed to 284 units of insulin glargin. People with T2D who were in the group using icodec achieved the same HbA1c results while taking less insulin.

While these data are promising, it will be necessary to wait to see the results of studies conducted in people living with T1D and to determine how to manage dose adjustments (e.g., need for rapid dose reduction), as well as unforeseen situations (e.g., hospitalization, prolonged physical activity).


  • Bajaj, Harpreet S et al. “Switching to Once-Weekly Insulin Icodec Versus Once-Daily Insulin Glargine U100 in Type 2 Diabetes Inadequately Controlled on Daily Basal Insulin: A Phase 2 Randomized Controlled Trial.” Diabetes care vol. 44,7 (2021): 1586-1594. doi:10.2337/dc20-287

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