NPH insulin is classified as which type of insulin?

NPH insulin is classified as which type of insulin?

• A. Short-acting
• B. Rapid-acting
• C. Intermediate-acting
• D. Long-acting

Answer: (C)

Insulin duration classifications explain why NPH is considered intermediate-acting. NPH is formulated with protamine to slow absorption, giving a slower onset and a longer duration than rapid-acting and short-acting insulins, but not as long or as flat a profile as long-acting analogs. Typical onset is about 1–2 hours, with a peak around 6–12 hours after injection and a total duration of roughly 14–18 hours, providing basal coverage with a noticeable peak. Its cloudy suspension and need for gentle mixing reflect the protamine-delayed release that creates this intermediate timing.

Insulin duration classifications explain why NPH is considered intermediate-acting. NPH is formulated with protamine to slow absorption, giving a slower onset and a longer duration than rapid-acting and short-acting insulins, but not as long or as flat a profile as long-acting analogs. Typical onset is about 1–2 hours, with a peak around 6–12 hours after injection and a total duration of roughly 14–18 hours, providing basal coverage with a noticeable peak. Its cloudy suspension and need for gentle mixing reflect the protamine-delayed release that creates this intermediate timing.