Basal, long acting or background insulin is an insulin that when administered into the subcutaneous fat under the skin is absorbed slowly into the blood stream. There are many basal insulins listed in order of duration of action:
Protaphane/NHP
Levemir (insulin detemir)
Lantus (insulin glargine U100)
Toujeo (insulin glargine U300)
Tresiba (insulin degludec)