What is rapid-acting insulin?

Rapid-acting insulin (also called fast-acting) is commonly used by people with type 1 diabetes to help them control their blood glucose levels. However, it can also be prescribed to people with type 2 diabetes. This medication can be injected subcutaneously using an insulin pen or can be administered with an insulin pump. When injected under the skin, rapid acting insulin starts to work very fast in reducing high blood sugar levels which arises after eating. It is usually taken right before a meal, or together with a meal. It is usually prescribed together with long acting insulin to provide blood sugar levels throughout the day and after meals.

Rapid-acting insulin peak times, onset and duration

Onset refers to the amount of time it takes before the insulin reaches the blood and starts to reduce blood glucose. The peak is the period of time when the insulin is working the best at reducing blood sugar levels. Duration refers to how long the insulin works in the body to reduce blood sugar levels. Rapid acting insulin has an onset time of between 10 to 30 minutes, the peak period is generally 1 to 2 hours and the duration period is between 2 to 4 hours.

Types and brands

Insulin lispro

Humalog is a brand name of insulin lispro, which helps to treat type 1 diabetes in adults. Insulin lispro is a man made insulin which mimics the work of the natural hormone in controlling blood sugar levels. Insulin lispro can be prescribed together with oral diabetes medications to treat type 2 diabetes in adults. After injection, insulin lispro starts to work after 15 minutes and peaks after 1 hour.

Insulin aspart

Novolog is a brand name of insulin aspart. Insulin aspart is a rapid acting insulin which works by lowering high blood sugar levels. It can be used in combination with intermediate acting and long acting insulin. This medication is injected under the skin using an insulin pen or into a vein with an IV. You should not inject this medication on the same spot twice. It is advisable you eat within 5 to 10 minutes after taking this medication.

Insulin glulisine

Apidra is a brand name of Insulin glulisine. Insulin glulisine works faster compared to regular insulin in lowering blood sugar levels. It is normally taken together with long acting insulin. You should not take this medication in larger or smaller amount than what is recommended by your doctor. After taking insulin glulisine, you should eat within 15 minutes. Insulin glulisine is only part of a treatment program which also includes exercise, diet, weight control and blood sugar testing. Make sure you follow carefully the instructions given by your doctor.

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.