Insulin lispro protamine suspension (ILPS) is a protamine-based, intermediate-acting insulin formulation of the short-acting analog insulin lispro: Insulin lispro (LysB28, ProB29 human insulin) is formed by switching lysine and proline amino acids at positions B28 and B29 (Figure 1).

What is the difference between lispro and lispro protamine?

Insulin lispro is a fast-acting insulin. Insulin lispro protamine is an intermediate-acting insulin. This combination insulin starts to work within 10 to 20 minutes after injection, peaks in 2 hours, and keeps working for up to 24 hours.

What insulin contains protamine?

Because neutral protamine Hagedorn (NPH) insulin includes protamine, it might be anticipated that NPH insulin-dependent diabetic patients would develop sensitivity to protamine.