Insulin therapy is a critical part of treatment for people with type 1 diabetes and also for many with type 2 diabetes. The goal of insulin therapy is to maintain blood sugar levels within your target range.

Insulin is usually administered in the fat under your skin using a syringe, insulin pen or insulin pump. Which insulin regimen is best for you depends on factors such as the type of diabetes you have, how much your blood sugar fluctuates throughout the day and your lifestyle.

Each insulin type is characterized by:

  • How long it takes to begin working (onset)
  • When it's working the hardest (peak)
  • How long it lasts, ranging from about 3 to 26 hours

Many types of insulin are available. Here's how they compare. Keep in mind that your doctor may prescribe a mixture of insulin types to use throughout the day and night.

Insulin type and name Onset Peak How long it lasts


Insulin aspart (NovoLog)

Insulin glulisine (Apidra)

Insulin lispro (Humalog)

5-15 min. 45-75 min. 3-4 hours


Insulin regular (Humulin R, Novolin R)

30-45 min. 2-4 hours 6-8 hours


Insulin NPH (Humulin N, Novolin N)

2 hours 4-12 hours 16-24 hours


Insulin glargine (Lantus/ Toujeo)

Insulin detemir (Levemir)

2 hours No clear peak 14-24 hours

In some cases, premixed insulin — a combination of specific proportions of intermediate-acting and short- or rapid-acting insulin in one bottle or insulin pen — may be an option.

Sept. 27, 2016