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 keep your blood sugar levels within a target range.

Insulin is usually injected in the fat under your skin using a syringe, insulin pen or insulin pump tubing. Which insulin is best for you depends on a number of factors. These factors include the type of diabetes you have, how much your blood sugar changes throughout the day and your lifestyle.

Many types of insulin are available and they vary by:

  • How long they take to begin working (onset)
  • When they reach their maximum effect (peak)
  • How long they last

Your doctor may prescribe a mixture of insulin types to use throughout the day and night. Sometimes, premixed insulin may be an option. Premixed insulin combines specific proportions of intermediate-acting and short- or rapid-acting insulin in one bottle or insulin pen.

This chart shows how individual insulins compare:

Insulin type and name Onset (approximate) Peak (approximate) How long it lasts (approx.)

Rapid-acting (injected)

Insulin aspart (NovoLog, Fiasp)

Insulin glulisine (Apidra)

Insulin lispro (Humalog, Admelog)

3-15 minutes 45-75 minutes 2-4 hours

Rapid-acting (inhaled)

Insulin human (Afrezza inhalation powder)

12 minutes 35-45 minutes 1.5-4.5 hours


Insulin regular (Humulin R, Novolin R)

30 minutes 2-4 hours 5-8 hours


Insulin NPH (Humulin N, Novolin N, Novolin ReliOn Insulin N)

1-2 hours 4-12 hours 8-24 hours


Insulin glargine (Lantus, Basaglar)

Insulin detemir (Levemir)

2 hours No pronounced peak 14-24 hours


Insulin degludec (Tresiba)

Insulin glargine (Toujeo)

1-6 hours No pronounced peak 36-40 hours
Last Updated: 07-27-2019
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