Humulin N is an intermediate-acting insulin medication used to control blood sugar levels in individuals with diabetes. It contains human insulin synthesized through recombinant DNA technology, mimicking the insulin produced naturally in the body. This insulin works by lowering blood glucose levels by facilitating the uptake of glucose into cells for energy production. It is typically injected under the skin and has a slower onset and longer duration compared to short-acting insulins, making it suitable for maintaining blood sugar levels between meals and overnight.