Humulin N (insulin NPH, rDNA origin) is an intermediate-acting human insulin suspension manufactured by Eli Lilly and Company. It contains 100 units of insulin per milliliter and is supplied in a 10 mL multiple-dose vial, providing a total of 1,000 units per vial. Humulin N is a sterile, white, cloudy suspension of isophane insulin for subcutaneous injection only.

Compared to regular human insulin, Humulin N has a slower onset of action and a longer duration of activity, making it suitable for once- or twice-daily dosing regimens. It is used to control blood sugar levels in adults and children with Type 1 or Type 2 diabetes mellitus. The typical starting dose for Type 2 diabetes is 0.2 units/kg/day, while Type 1 patients may require 0.5–1 unit/kg/day adjusted to individual needs based on blood glucose monitoring.

Humulin N should be stored in a refrigerator (36°F–46°F / 2°C–8°C) until opened; once in use, the vial may be kept at room temperature (below 77°F / 25°C) for up to 31 days. Do not use if the insulin appears clear or contains lumps or particles. This product requires a prescription or, in many states, is available over the counter. Dosage must be individualized by a healthcare professional based on regular blood glucose testing. Available at Costco Pharmacy as part of the Member Prescription Program.