Insulin is injected under the skin. An injection under the skin is called a subcutaneous injection. Insulin cannot be given in pill form because the acid in the stomach destroys insulin. Insulin may be given continuously by an insulin pump (See section on insulin pumps).
Different types of Insulin
There are many types of insulin. Insulin is divided into types based on how it is made. There is human insulin and analog insulin. Human insulin is the same as the insulin produced in your pancreas. Analog insulins are slightly different than human insulin to allow them to work faster or slower than regular human insulin. Human and analog insulin are divided into types based on how fast it begins to lower blood sugar (onset) and how long it continues to work in the body (duration).
- Short-acting or regular insulin. This type of insulin takes 30 minutes to start working to lower blood sugar and lasts 5 to 8 hours. It is usually taken 30 minutes before meals.
- Intermediate-acting or NPH insulin. This type of insulin takes 1 to 3 hours to start lowering blood sugar and lasts 12 to 16 hours. It is usually taken before breakfast and in the evening.
- Premixed. This type of human insulin is a combination of regular insulin and NPH insulin. It is taken twice daily usually 30 minutes before breakfast and 30 minutes before dinner.
- Fast-acting. This type of analog insulin starts to work in 15 minutes. It is usually taken right before a meal is eaten.
Novolog, Humalog, Apidra, Ademelog or Fiasp
- Long-acting. This insulin works slowly for 24 hours in your body. It is used to control your blood sugar between meals and while you sleep. It should be taken at the same time every day because it works for 24 hours.
Levemir, Lantus, Toujeo or Tresiba
- Premixed. This is a combination of fast and intermediate-acting analog insulin. It is taken twice daily usually 30 minutes before breakfast and 30 minutes before dinner.
Insulin pumps are small computerized devices that deliver insulin in two ways:
- In a steady measured and continuous dose (the "basal" insulin)
- As a surge ("bolus") dose, at your direction, around mealtime.
Doses are delivered through a flexible plastic tube called a catheter. With the aid of a small needle, the catheter is inserted through the skin into the fatty tissue and is taped in place. The needle is removed leaving the catheter in place.
The insulin pump is not an artificial pancreas (because you still have to monitor your blood sugar level), but pumps can help some people achieve better control, and many people prefer this continuous system of insulin delivery over injections.
Pumps can be programmed to release small doses of insulin continuously (basal), or a bolus dose close to mealtime to control the rise in blood sugar after a meal. This system most closely mimics the body's normal release of insulin.
Ask your primary care provider if you are interested in an insulin pump. You may need to be seen by an endocrinologist- someone who specializes in diabetes. Check with your insurance carrier to see if insulin pumps are covered under your policy.
All insulin pumps have a toll free number on the back in case you have questions or problems with your pump.
Note: It is a good idea to carry extra insulin pump supplies with you, especially if you will be in the hospital.