What is bolus insulin?

It is the man-made insulin that is taken with a meal to help regulate blood sugar levels after eating. When you eat, the level of blood glucose rises. The pancreas will release insulin to respond to the rise in blood glucose. Bolus insulin is also known as background insulin and helps keep blood sugar at an optimal level during fasting periods. It is normally used in patients with type 1 diabetes because their pancreas does not make the natural hormone. Insulin is the hormone that helps to regulate blood glucose levels. Insulin bolus is supposed to be administered via injection with a syringe.

Bolus insulin brands

Bolus insulin brands are usually classified into 2 main insulin classes: rapid-acting and short-acting insulin.

Rapid-acting insulin

Rapid-acting insulin, which is also known as fast-acting insulin, works very fast to reduce the increase in blood sugar after eating a meal. Rapid-acting insulins are normally taken just before you eat or together with food. The following are examples of bolus insulin that belong to this class of rapid acting insulin.


Novolog contains an active ingredient called insulin aspart. Insulin aspart works very fast to stabilize blood glucose levels. Novolog starts to work after about 20 minutes and can last up to 5 hours. Insulin aspart can be injected before or after a meal.


Humalog is the brand name of insulin lispro, which is marketed and produced by a company called Eli Lilly. When you inject insulin lispro under the skin, it starts to work within 15 minutes. Humalog has a duration of about 2 to 5 hours. Compared to other insulins, Humalog is fast-acting, making it useful for diabetic patients who want to control their blood glucose during mealtimes.


Apidra is a rapid-acting insulin that contains the active ingredient insulin glulisine. Insulin glulisine has an onset time of about 15 minutes and a duration of 2 to 4 hours. Apidra can be used to control blood sugar in type 1 and type 2 diabetic people.

Short-acting insulin

Short-acting insulins, also called neutral or regular insulins, are usually administered before meals. Short-acting insulin works quickly, but not as fast as rapid-acting insulin, to reduce high blood sugar. The following are examples of short acting basal insulin.

Humulin R

Humulin R is a short-acting insulin that is normally administered 20 to 45 minutes before a meal. Humulin R contains the active ingredient called insulin regular, which starts to work after 30 minutes following an injection. Insulin regular can last up to 4 hours or more.

Novolin R

Novolin R, which is also called human regular insulin, is a short-acting insulin that is prescribed to patients with type 1 and type 2 diabetes. It starts to work within 30 to 60 minutes and can last up to 8 hours.

Insulin bolus dosing

The dosage of bolus insulin will be different depending on the brand. The number of injections and time between injections depends on your medical condition. Bolus insulins are meant to be taken before you eat. Your doctor may advise you to take insulin bolus during or immediately after you eat to prevent the risk of hypoglycemia occurring. If you have any queries regarding the timing of your injections, speak to your health-care provider.

Disclaimer: Please note that the contents of this community article are strictly for informational purposes and should not be considered as medical advice. This article, and other community articles, are not written or reviewed for medical validity by Canadian Insulin or its staff. All views and opinions expressed by the contributing authors are not endorsed by Canadian Insulin. Always consult a medical professional for medical advice, diagnosis, and treatment.