| Insulin type | Onset of action | Peak | Duration of action | Comments |
| Lispro, aspart, glulisine | 5 to 15 mins | 45 to 75 mins | 2-4 h | Give immediately before meal |
| Regular | about 30 mins | 2-4 h | 5-8 h | Give ~ 30 min before meal |
| NPH | about 2 h | 4 to 12 h | 18 to 28 h | Can cause protamine Ab prod |
| Insulin glargine | about 2 h | No peak | 20 to >24 h | Once daily (a.m. or p.m) |
| Insulin detemir | about 2h | 3-9 h | 6 to 24 h* | Once daily |
| NPL | about 2h | 6 h | 15 h | |
| Insulin degludec | about 2h | No peak | >40 h |
NPH: neutral protamine Hagedorn; NPL: neutral protamine Lispro.
* Duration of action is dose-dependent. At higher doses (≥0.8 units/kg), the mean duration of action is longer and less variable (22 to 23 h).
* Duration of action is dose-dependent. At higher doses (≥0.8 units/kg), the mean duration of action is longer and less variable (22 to 23 h).
Pearls
Insulin Glargine should never be mixed with other insulin.
Patients must eat within 15 minutes of taking Insulin Lispro. Insulin lispro is a rapid-acting insulin that should be injected within 15 minutes before a meal or immediately after a meal to avoid hypoglycemia.
NPH and Lente are intermediate-acting insulin types with an onset of action of 1–3 hours.
Ultralente and insulin glargine are long-acting types with an onset of action of 2–4 hours and 1–2 hours, respectively.