What type of insulin has no peak level and a long duration of action?

The type of insulin that has no peak level and a long duration of action is glargine. This insulin is a long-acting formulation designed to provide a consistent release of insulin over an extended period, typically around 24 hours. The lack of a pronounced peak means that glargine helps to maintain steady blood glucose levels without the risk of significant fluctuations, which is particularly beneficial for people who require basal insulin therapy as part of their diabetes management.

Glargine achieves a steady state due to its unique formulation, which allows it to precipitate in the subcutaneous tissue and gradually dissolve into circulation. This characteristic enables a more stable insulin level, mirroring the natural basal secretion of insulin by the pancreas, and helps to avoid the peaks associated with rapid-acting or intermediate-acting insulins.

In contrast, regular insulin has a notable peak effect that occurs a few hours after administration, and lispro is a rapid-acting insulin that also has a peak action shortly after injection. Detemir, another long-acting insulin, provides a more gradual release than regular insulin but still has a slight peak, making glargine the best option for individuals looking for a long-acting insulin without peaks.