Is NPH a long acting insulin?

No, NPH (Humulin N, Novolin N) insulin is considered an intermediate-acting insulin. NPH insulin has a longer duration of action than the rapid-acting insulins (Novolog, Apidra, Humalog) and the short-acting insulins (Humulin R, Novolin R).

NPH insulin usually has an onset (starts to work) about 1 to 3 hours after injection, peaks 4 to 12 hours later, and is effective for about 12 to 16 hours.

However, it's important to remember that the onset and duration of action of any insulin may vary individually or at different times in the same individual.