Treating diabetes, choosing the right insulin

There are many types of insulins used to treat diabetes, and they are grouped according to how quickly the insulin takes effect and how long the effect lasts.

Types of insulin include:

  • Quick-acting insulins.
  • Short-acting insulin.
  • Medium-acting insulin.
  • Long-acting insulins.
  • Premixed insulin.

Which insulin type is best for you?

The doctor will work with the patient to choose the insulin that is best for the patient and their type of diabetes. This choice depends on many things.

  • How the body responds to insulin (the time it takes for the body to absorb insulin and the duration of the effect varies from person to person).
  • Lifestyle choices: The types of foods eaten, alcohol intake, and exercise all affect the way the body uses insulin.
  • Willingness to inject insulin as many times a day.
  • Frequency of checking blood glucose.
  • Age.
  • Glucose management goals.

Quick-acting inhaled insulin is approved by the U.S. Food and Drug Administration (FDA) for pre-meal dosing for the treatment of type 1 and type 2 diabetes. The drug reaches peak blood levels about 15 to 20 minutes after dosing and is cleared from the body within 2 to 3 hours. For people with type 1 diabetes, rapid-acting inhaled insulin is used in combination with long-acting insulin.

The following table lists the types of insulin injected, including details about onset of action (how long before insulin enters the bloodstream and begins to lower blood glucose), peak drug duration (the optimal time period for lowering blood glucose), and duration (the duration of the insulin’s effect). These three aspects may vary between insulin types. The last column of the table lists information about the different insulin types in relation to meal timing and their role in blood glucose management.

Insulin type Time to onset of action Peak Duration Role in blood glucose management
Quick-acting insulin
Lysine insulin 15 to 30 minutes 30 to 90 minutes 3~5 hours Quick-acting insulins meet the need for insulin injections while eating. These insulins are usually used with long-acting insulins.
Menthol insulin 10 to 20 minutes 40 to 50 minutes 3~5 hours
Lysergic acid insulin 20 to 30 minutes 30 to 90 minutes 1~2.5 hours
Short-acting insulin
Regular insulin 30 minutes to 1 hour 2 to 5 hours 5~8 hours Short-acting insulin meets the need to eat within 30 to 60 minutes of dosing.
Regular insulin 30 minutes to 1 hour 1 to 2 hours 2~3 hours
Medium-acting insulin

Neutral fisetin zinc insulin

1 to 2 hours 4 to 12 hours 18~24 hours Medium-acting insulins meet half-day or overnight insulin requirements. These insulins are usually used in combination with rapid-acting or short-acting insulins.
Long-acting insulin
Glycoplanin insulin 1 to 1.5 hours No peak time, insulin works at steady levels 20 to 24 hours Long-acting insulins meet the insulin needs for about a full day. These insulins are usually used in combination with rapid-acting or short-acting insulins when needed.
Dietary insulin 1 to 2 hours 6~8 hours Up to 24 hours
Deguel Insulin 30 to 90 minutes 30~90 minutes 42 hours
Pre-mixed insulin
Arginine Zinc Recombinant Human Insulin 70/30 30 minutes 2 to 4 hours 14~24 hours These products are usually applied before meals, two to three times a day.
Arginine zinc biosynthetic human insulin 70/30 30 minutes 2 to 12 hours Up to 24 hours
Mentoinsulin 70/30 10 to 20 minutes 1~4 hours up to 24 hours
Arginine Zinc Recombinant Human Insulin 50/50 30 minutes 2 to 5 hours 18~24 hours
Arginine zinc recombinant lysine insulin mix injection 75/25 15 minutes 30 minutes to 2.5 hours 16 to 20 hours
*Pre-mixed insulin combines specific amounts of intermediate-acting and short-acting insulin in the same bottle or pen (the number after the generic name indicates the percentage of each insulin).

How are insulin doses scheduled?

Use insulin as prescribed by your doctor. The time span between insulin injections and meals may vary depending on the type of insulin.

But in general, the timing of injections should be coordinated with meal times. As per the table above, the “onset of action” column shows when insulin starts to work in the body. It is best to make sure that the insulin works when the body absorbs food. Good timing helps avoid hypoglycemia.

  • Quick-acting insulin: About 15 minutes before a meal.
  • Short-acting insulin: About 15 minutes before a meal.
  • Short-acting insulin: 30 to 60 minutes before a meal.
  • Medium-acting insulin: 1 hour before a meal.
  • Premixed insulin: depending on the type of drug, usually 10 minutes or 30 to 45 minutes before a meal.

Special exceptions for insulin dose and dosing time

Timing of long-acting insulin is not related to mealtime. Regardless of the timing of meals, disulfiram insulin should be administered once or twice daily. Patients on glargine insulin should be dosed once daily at the same time. Degludec insulin should be applied once daily with flexible timing. However, some patients require a combination of long-acting insulin with short-acting insulin, or another diabetes medication taken at mealtime.

Quick-acting insulin can also be administered immediately after a meal, rather than 15 minutes before a meal. Some medications can also be taken at bedtime.

For more information on when to take insulin, read the “Dosage and Administration” section of the product insert, or consult your doctor.