Flexible Injection Plans Using Basal and Bolus Insulins

Each insulin dose you take reaches its peak effect at a particular time after the injection. For example, the short-acting insulin you took at breakfast affects your blood glucose level just before lunch.

In a person without diabetes, the pancreas delivers a steady, low level of insulin into the blood all day long. This is called the basal level of insulin. At mealtimes, the pancreas also releases higher amounts of insulin, called a bolus dose. As more carbohydrates are eaten, a bigger insulin bolus is released.

The result: blood glucose stays in the normal zone throughout the day (the yellow band shown at the top of the chart):

Insulin Levels Chart 

Once you understand how and when insulin works in your body - and how that relates to your food intake and physical activity - you can adjust your doses to stay in your blood glucose target range. The goal is to come as close as possible to the action of a healthy insulin-producing pancreas.

With FIT:

  • You may take long-acting insulin once or twice a day, plus bolus injections of insulin three or more times a day with a syringe, pen, or pump. That way, you mimic the steady insulin-delivery action of a healthy pancreas.  

  • You will test your blood glucose four or more times a day, typically before meals, snacks and bedtime. The testing helps you to fine-tune each mealtime bolus dose based on your actual needs. Frequent testing can also help you spot those times of day when your blood glucose is often out of range, so that you can adjust your therapy.

The regimens below are examples of injection plans that are commonly used for flexible insulin therapy (FIT). Remember, FIT is an individualized approach based on age, lifestyle, and other factors. The regimen prescribed by your doctor may differ from the examples you see here.

These injection plans are designed to imitate the effect of a healthy pancreas.

  • They use faster-acting insulin before mealtimes to cover breakfast, lunch, and dinner.

  • In addition, slower-acting insulin taken once or twice a day provides a constant low level of insulin in the body.

    Flexible Regimen - For example only*

    Insulins Regular- or rapid-acting and intermediate-acting.
    Number of injections Four per day.
    Injection times

    Injection 1:

    Up to 15 minutes before breakfast if using rapid- and intermediate-acting insulin mixed in one syringe**

    30 minutes before breakfast if using regular- and intermediate-acting insulin mixed in one syringe.

    Injection 2:

    Up to 15 minutes before lunch if using rapid-acting insulin.

    30 minutes before lunch if using regular-acting insulin.

    Injection 3:

    Up to 15 minutes before dinner if using rapid-acting insulin.

    30 minutes before dinner if using regular-acting insulin.

    Injection 4:

    2 to 4 hours before bed with intermediate-acting insulin.

    Dosage performance

    Intermediate insulin starts working in two to four hours. The morning dose covers you throughout the day and the evening dose works through the night.

    Comments ** This regimen does not use LantusĀ® (insulin glargine). Lantus cannot be mixed with any other insulin.

    * Information on the BD web site should not be used as a substitute for professional medical advice. Please contact your doctor to discuss your diabetes care.

    Lantus is a trademark of Aventis Pharma Deutschland, GmbH


The BD Diabetes Learning Center describes the causes of diabetes, its symptoms, and diabetes complications such as retinopathy and neuropathy. This site contains detailed information about blood glucose monitoring, insulin injection and safe sharps disposal. Interactive quizzes, educational literature downloads and animated demonstrations help to teach diabetes care skills.

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