What Is Regular Insulin Used For?
Many people are surprised to learn that many insulin medications are available over the counter (without a prescription). Regular human insulin, NPH insulin (such as Humulin N or Novolin N), and mixtures of the two types do not require a prescription, even though they are stored "behind the counter" in the pharmacy, since they must be refrigerated. Newer forms of insulin require a prescription. If you would like your insurance (or Medicaid or Medicare Part D) to cover regular insulin, you will need a prescription from your healthcare provider.
Even though you don't need a prescription for regular insulin, it is very important that you use it only under your healthcare provider's supervision. Insulin is a potent and potentially dangerous drug. Taking too much can easily result in death (see Humulin R Overdose or Novolin R Overdose). You should not take regular insulin if you do not have diabetes, as this can be extremely dangerous. People without diabetes sometimes abuse insulin (often in combination with steroids) in an attempt to enhance athletic performance.
It should be noted that the concentrated form of this insulin (U-500 Humulin R) always requires a prescription. The standard concentration (U-100 regular insulin) does not.
Even though it is made in a laboratory, regular insulin is identical to the insulin produced by the human body. Insulin is a hormone that is naturally produced by the pancreas. This hormone is important for several functions, such as controlling blood sugar. Insulin helps the cells of your body remove glucose ("sugar") from your bloodstream. This sugar fuels your body's cells, giving them the energy they need to work properly. You may need to take insulin if your pancreas has trouble making enough insulin, which is the case in people with type 1 diabetes and in some people who have type 2 diabetes.
Regular insulin is a short-acting insulin medication. It works more quickly than intermediate- or long-acting insulins but less quickly than rapid-acting insulins. It starts working relatively quickly, produces a peak in insulin levels, and drops off relatively quickly. It is designed to help control the blood sugar spike that occurs after meals. Most people who take regular insulin will also need a long-acting insulin as well, to provide a steady background level of insulin to help control blood sugar throughout the day.