How NovoLog® Works 

Remember that although there is only one NovoLog® insulin, you might hear your health care providers refer to it by a few other names. As an insulin that you take at mealtime, NovoLog® is often called “mealtime” or "bolus" insulin. Because it goes to work quickly, it is also sometimes called “rapid-acting” or “fast-acting” insulin. And, because it is a slightly changed man-made version of insulin, it is also called analog insulin.

NovoLog® helps control mealtime blood sugar spikes

Mealtime insulin therapy with NovoLog® tries to mimic the normal pattern of how the body responds to rising blood sugar after meals. In a person who doesn't have diabetes, the pancreas releases a short burst, or "bolus," of insulin to handle the increase in blood sugar from each meal. As a bolus, or fast-acting, insulin, NovoLog® closely mimics these bursts, helping to control mealtime blood sugar spikes that happen in people with diabetes.

Besides bolus insulin, there is also basal insulin. In fact, you may already be taking “long-acting” basal insulin. Maybe at night or in the morning—sometimes both. In people without diabetes, a steady amount of basal insulin is released into the blood day and night. This insulin helps control blood sugar between meals and during sleep.

In some people with type 2 diabetes, especially those whose bodies are still naturally producing some insulin, replacing the natural basal insulin release with a man-made long-acting insulin is enough to control their blood sugar throughout the day. However, as the pancreas produces less insulin, stops producing insulin altogether, or the body has more trouble using it correctly, adding a bolus (mealtime) insulin may become necessary. 

Long-acting basal insulin plus a fast-acting bolus insulin, such as NovoLog®, working together to control blood sugar is often called “basal-bolus therapy”. 

For those with type 1 diabetes, treatment will likely start with basal- bolus therapy on day 1.

How NovoLog® Works
(7:12 min.)

A video that shows the science behind how NovoLog® works

NovoLog® is designed to work like the insulin your body makes. It is changed slightly so that it works more quickly than regular human insulin. And it closely mimics the insulin your body makes.

NovoLog® compared to the body’s own insulin

As you can see from this graph, NovoLog® closely mimics the pattern of how insulin is used in the body after eating. This can help you control your blood sugar and may allow you to get closer to your target blood sugar goal. 


NovoLog® helps control mealtime blood sugar spikes.

  • As a fast-acting insulin analog, NovoLog® acts quickly, so you must eat within 5 to 10 minutes after taking it
  • It works to cover your blood sugar spikes the first 1 to 3 hours and stays active in your body for 3 to 5 hours
    • This makes sense because it closely mimics the body's insulin pattern that happens when you eat
    • Blood sugar peaks 1 to 2 hours after you eat and can still be high for at least 4 hours afterward
    • This means that NovoLog® can help you control blood sugar spikes at mealtime
  • Controlling your blood sugar at mealtime with NovoLog® can help lower your A1C when taken with a long-acting insulin
  • Even though NovoLog® is a “fast-acting insulin,” it will take time to see how NovoLog® affects your A1C
  • NovoLog® is not a quick fix or a temporary solution; even after your A1C improves you will still need to take it to help manage your diabetes

With NovoLog®, you work with your diabetes care team to adjust your insulin dose based on your eating and activity levels. You may also need to adjust the dose if you have high or low blood sugar. When using NovoLog® in basal-bolus therapy, between 50% to 70% of your total insulin dose can be NovoLog® as the bolus insulin, with the rest of your insulin needs taken care of by your long-acting basal insulin.

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