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A patient guide for understanding insulin

A Patient Guide For Understanding Insulin

What Is Insulin?

Insulin is a hormone made by your pancreas that helps to lower your blood sugar levels. Insulin helps lower your blood sugar levels by storing the extra blood sugar in your liver. There are three characteristics to insulin. Onset is the time before insulin reaches the bloodstream and begins lowering your sugar levels. Peak is the time during which insulin as at its highest concentration to lower your sugar levels. Finally, duration is how long insulin continues to lower your sugar levels.

Information on Rapid-Acting Insulin

Rapid-acting insulin begins to work about 15 minutes after injection, peaks in about 1 hour, and continues to work for 2 to 4 hours.

Information on Short-Acting Insulin

Short-acting insulin usually reaches the bloodstream within 30 minutes after injection, peaks anywhere from 2 to 3 hours after injection, and is effective for approximately 3 to 6 hours.

Information on Intermediate-Acting Insulin

Intermediate-acting insulin generally reaches the bloodstream about 2 to 4 hours after injection, peaks 4 to 12 hours later, and is effective for about 12 to 18 hours.

Information on Long -acting Insulin

Long-acting insulin reaches the bloodstream several hours after injection and tends to lower glucose levels fairly evenly over a 24-hour period.

What type of Insulin is Right For Me?

The insulin that’s right for you depends on what type of diabetes you have. Patients with type I diabetes may start with two injections of insulin per day of two different types of insulin and may progress to using four injections per day. Patients with type II diabetes usually start with one injection a day if their oral medication fails. Because patients may have oral medications that stop working, they may need to start two injections per day of two different types of insulin and may need to progress to three or four injections per day.

Patient Education on Insulin

There are various types of insulin delivery. These methods include using a syringe to draw up the insulin from a vial, using an insulin pen, and using an insulin pump. “The place on your body where you inject insulin affects your blood glucose level. Insulin enters the blood at different speeds when injected at different sites. Insulin shots work fastest when given in the abdomen. Insulin arrives in the blood a little more slowly from the upper arms and even more slowly from the thighs and buttocks. Injecting insulin in the same general area (for example, your abdomen) will give you the best results from your insulin. This is because the insulin will reach the blood with about the same speed with each insulin shot.”

It is important to remember to rotate the injection sites for insulin. Make sure not to inject insulin at the exact same spot, but next to each spot. If you inject insulin at the exact same spot hard lumps may develop in that area, putting the insulin in the refrigerator (because insulin shots are more painful when cold). Insulin stored at room temperature lasts for one month.



(1) American Diabetes Association. Available from: Accessed November 1, 2018.

(2) Standards of medical care in diabetes-2018. Pharmacologic approaches to glycemic treatment. American Diabetes Association. Available from: Accessed October 3, 2018


Artur Dzhurinskiy
22 July, 2019

Written by

My name is Artur Dzhurinskiy and I graduated from St. Louis College of Pharmacy in 2014 with a doctor of pharmacy degree. Through my academics I gained valuable experience learning about various medications that more:

2 thoughts on “A Patient Guide For Understanding Insulin

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