What Is Insulin?

How insulin affects blood sugar

Insulin is a hormone made naturally in your pancreas. Insulin helps move blood sugar, or glucose, into your cells. Since the body uses blood sugar for fuel, insulin is very important.

Without enough insulin, blood sugar can’t get into your cells. Instead, it stays in your bloodstream. When blood sugar levels are too high, the condition is called hyperglycemia. Hyperglycemia can lead to the signs and symptoms of diabetes, like weight loss, feeling extreme thirst or hunger, or needing to go to the bathroom more often.

What are the different types of insulin?

Different insulin therapies are grouped by when they start to work, when their effect on blood sugar is greatest, and how long they work. Insulins are available in these types:

• Long-acting (basal). Long-acting insulins, like Levemir®, work to control blood sugar between meals and when you sleep. It’s taken either once or twice a day at the same time every day, often with your evening meal or at bedtime to help give up to 24-hour insulin coverage. This may be the first insulin prescribed for people with type 2 diabetes
• Rapid or fast-acting (bolus). Fast-acting insulin, like NovoLog®, is taken shortly before mealtime. This insulin works quickly to control the rapid rise in blood sugar after meals. Fast-acting insulin imitates the body’s natural release of insulin at mealtime
• Intermediate-acting. This insulin takes up to 3 hours to start working and lasts for 12 to 16 hours
• Premixed. Premixed insulin, like NovoLog® Mix 70/30, combines the action of a fast-acting and long-acting insulin

Why are there different types of insulin?

All types of insulin help to keep diabetes under control. No one type of insulin is right for everyone as each person’s insulin needs are different. Also, each person’s insulin needs may change over time. Your doctor and diabetes care team will help you decide the best insulin for you.