Know the Types of Insulins: The Beginning, Peak and Duration


Like all medicines used, once you know your characteristics better, treatment and adherence become easier and more enjoyable.

The main function of insulin is to carry glucose into cells, where it is used as energy.

When we feed, the pancreas is stimulated to produce insulin, thus carrying excess glucose into the various organs of the human body for use and storage.

And when are we fasting?

During the fast, insulin is also produced. Remembering that also during the fasting the insulin must load the glucose into the cells, so that they have energy. In this period, glucose comes from deposits present, mainly in the liver and muscles.

As we can see, even in our body, insulin acts in different ways, with an action that is continuous, which is that of fasting, and another that happens in peaks, which is that which happens in the meal.

In order to try to mimic what happens in the body without diabetes, the used insulins also have different characteristics: according to the beginning period of their action (when they begin to act), their maximum action (called peak action) and time in which it remains acting (duration of action).

Fast and Ultrafast Insulin

Insulins used for the bolus are fast and ultra fast calls. They have as action the feeding period, promoting a good glycemic control in the periods close to feeding.

Fast or regular insulin begins to act in 30 to 60 minutes and has its peak of action in 2 to 3 hours and duration of action of 6 hours and 30 minutes. Therefore, it should be used 30 to 45 minutes before the meal. Ultrafast insulin – lispro, aspart or glulisine – begins to act in 10 to 15 minutes, has its peak of action in 1 to 2 hours and duration of action of 3 to 5 hours. Therefore, it should be used in less than 15 minutes before the meal, or even during the meal. The latter has a lower risk of hypoglycemia than the rapid one.

Slow and Ultra slow insulins

The insulins used for the basal role are the slow and ultralent. Its main goal is to maintain stable glycemia between meals.

NPH insulin is the only representative of slow insulins. It begins to act in 1 to 3 hours, has its peak action in 5 to 8 hours and duration of action of up to 18 hours. Ultralent insulin is represented by Insulin Detemir – with onset of action in 1 to 2 hours, discrete peak of action in 2 hours and duration of action of 16 to 24 hours – and Insulin Glargine – with onset of action in 1 to 2 hours , absence of peak action and duration of action of up to 24 hours.

Use of Insulin in Type 1 and Type 2 Diabetes

Patients with type 1 diabetes, as they do not produce any insulin, should always use both types of insulin – called full insulinization. When feeding, they should use fast or ultra-fast insulins, respecting their application times. If your capillary glycemia (or dextro) is elevated before feeding, you should use a larger dose to correct this value, in addition to that required for feeding. For basal insulin, they should use the slow or ultralast, even if fasted, to maintain adequate levels of their blood glucose. Users of the subcutaneous insulin pump use ultrafast insulin continuously for this purpose.

In patients with type 2 diabetes, full insulinization is only performed in later stages of disease progression, when what is called “pancreas failure” occurs. That is, the pancreas, over time, fails to produce enough insulin to fulfill its functions of maintaining glycemia during fasting and covering the excess glucose from the diet. In earlier stages, use may be necessary when blood glucose levels are very high, or in situations where oral medications are contraindicated, such as during surgery or serious illness.