How long does Tresiba last?

Tresiba is an ultra long-acting basal insulin that according to the manufacturer Novo Nordisk has a duration beyond 42 hours. It differs from other long-acting insulins, such as Lantus and Levemir, which have a shorter duration of up to 24 hours. While Tresiba is taken once a day, many diabetics who take the shorter-acting variants tend to split their dose in two to prevent it from tapering off towards the end of its lifecycle. The advantage of Tresiba is the stability it offers in blood glucose, but due to its long duration, it offers little flexibility to make dose adjustments if you have variable basal needs due to for example exercise or alcohol consumption on certain days.

The 42-hour duration length does however not mean that you have full coverage during this period. If you miss your dose your blood glucose will start climbing. Since being on Tresiba, I’ve forgotten to take my morning dose twice and both times, my blood sugar has been high in the afternoon. While the insulin may have blood glucose-lowering effects beyond 42 hours, it doesn’t carry over until the next day if you miss a dose in my experience.