Talk with your healthcare provider prior to taking regular insulin if you have:
- Liver disease, such as liver failure, cirrhosis, or hepatitis
- Kidney disease, such as kidney failure (renal failure)
- Any allergies, including allergies to foods, dyes, or preservatives.
Also, let your healthcare provider know if you are:
- Pregnant or thinking of becoming pregnant (see Humulin R and Pregnancy or Novolin R and Pregnancy)
- Breastfeeding (see Humulin R and Breastfeeding or Novolin R and Breastfeeding).
Make sure to tell your healthcare provider about any other medications you are taking, including prescription and non-prescription medicines, vitamins, and herbal supplements.
(Click Precautions and Warnings With Regular Insulin to learn more, including information on who should not take the drug.)
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.