When you have type 1 diabetes, your body cannot make its own insulin. You will need insulin shots (injections) every day. Many people with type 2 diabetes also need insulin injections. You cannot take insulin by mouth or in any other form than injections.

Basal and Bolus Insulin Therapy

The insulin therapy that works most like the pancreas is basal and bolus therapy. This therapy combines rapid-acting insulin and long-acting insulin to manage diabetes. It is also known as ‘intensive diabetes management.’


Basal Insulin

  • Works over a long period of time. This is called long-acting insulin.

  • It is taken at the same time each day.

  • You will take the same dose each day.

Bolus Insulin

  • Works over a short period of time. This is called rapid-acting insulin.

  • Is taken before eating a meal or snack that has carbohydrates.

  • Brings high blood glucose back to target range.

  • This dose may be different each time you take a bolus dose of insulin.

  • The time that it is taken will change based on the times of your meals and snacks and blood glucose readings.

chart depicting the difference between bolus and basal insulin. Bolus has three large arches, whereas basal has a constant pattern

Types and Actions of Insulin

Types of Insulin



Starts to Work


Lasts For


Glargine (Lantus®)

Detemir (Levemir®)




In 4 hours

No peak

About 18-26 hours


Lispro (Humalog®)

Aspart (Novolog®)

Glulisine (Apidra®)




In 15 minutes

1 to 2 hours

3-4 hours

** You may hear about other types of insulin. If you need a different type of insulin therapy, we will let you know.


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