Insulin preparation	Onset of action	Peak	Duration of action	Comments
Rapid-acting insulin
Lispro (Humalog)	5 to 15 minutes	1 to 2 hours	4 to 5 hours	—
Aspart (Novolog)	5 to 15 minutes	1 to 2 hours	4 to 5 hours	—
Glulisine (Apidra)	5 to 15 minutes	1 to 2 hours	4 to 5 hours	—
Regular (recombinant) (Humulin R)	30 to 60 minutes	2 to 4 hours	8 to 10 hours	Inject 30 minutes before meal
Intermediate-acting insulin
Isophane (NPH) (Humulin N) Long-acting insulin	1 to 2 hours	4 to 8 hours	10 to 20 hours	—
Detemir (recombinant) (Levemir)	1 to 2 hours	Relatively flat	12 to 20 hours	Smoother curve than NPH; administered once or twice daily; available in pen form; can be kept without refrigeration for up to 42 days
Glargine (Lantus)	1 to 2 hours	Relatively flat	20 to 24 hours	Available in pen form
Mixed insulin
Multiple preparations (e.g., Humulin 70/30)	30 minutes	Dual peak	Up to 24 hours	Mixed insulin preparations may hinder tight glycemic control because the ratio of the two preparations cannot be altered