General Practice 2022

Insulin: what é, what it is for and when to take it

Table of contents:

Insulin: what é, what it is for and when to take it
Insulin: what é, what it is for and when to take it

Insulin is a hormone produced in the pancreas that is responsible for taking glucose from the blood into the cells to be used as a source of energy for the body's working processes.

The main stimulus for insulin production is the increase in blood sugar after meals. When the production of this hormone is insufficient or absent, as in diabetes, the sugar cannot be taken into the cells and, therefore, ends up accumulating in the blood and urine, causing complications such as retinopathy, kidney failure, injuries that do not heal and even favoring stroke, for example.



Diabetes is a disease that changes the amount of insulin produced, as it affects the ability of the pancreas to produce this hormone, which can be from birth, which is type 1 diabetes, or acquired throughout life, which is type 2 diabetes. In these cases, it may be necessary to use drugs to control sugar levels or even make use of synthetic insulin to simulate the action of what should be being produced by the body.

Better understand the symptoms and how to identify diabetes.

What is insulin for

Insulin has the ability to capture glucose that is in the blood, and take it to the body's organs, such as the brain, liver, fat and muscles, where it can be used to produce energy, proteins, cholesterol and triglycerides to give the body energy, or to be stored.

The pancreas produces 2 types of insulin:

  • Basal: is the continuous secretion of insulin, to maintain a constant minimum throughout the day;
  • Bolus: this is when the pancreas releases large amounts at once after each feeding, thus preventing food sugar from accumulating in the blood.

That is why, when a person needs to use synthetic insulin to treat diabetes, it is also important to use these two types: one that must be injected once a day, and another that must be injected always after the meals.

What regulates insulin production

There is another hormone, also produced in the pancreas, which has the opposite action of insulin, called glucagon. It works by releasing glucose that is stored in fat, liver and muscles into the blood, for the body to use when sugar levels are very low, such as during a fasting period, for example.

The action of these 2 hormones, insulin and glucagon, is very important to balance the amount of glucose in the blood, preventing it from being in excess or in lack, as both situations bring bad complications to the body.

When you need to take insulin

It is necessary to use synthetic insulin in situations where the body cannot produce it in the necessary amounts, such as in type 1 diabetes or severe type 2 diabetes. Understand better when it is necessary to start insulin use by diabetics.

Synthetic insulin in medicines mimics the body's insulin secretion throughout the day, both basal and bolus, so there are several types, which differ in how quickly they act on blood glucose:

1. Basal-acting insulin

They are synthetic insulins that mimic the basal insulin that is slowly released by the pancreas throughout the day, and can be of:

  • Intermediate action or NPH,such as Insulatard, Humulin N, Novolin N or Insuman Basal: lasts for up to 12 hours in the body, and can also be used to maintain an amount of constant insulin in the body;
  • Slow-acting, such as Lantus, Levemir or Tresiba: insulin that is released continuously and slowly over 24 hours, which maintains minimal action throughout the day.

Ultra-long-acting insulins are already being marketed, lasting up to 42 hours, which can provide greater comfort to the person, reducing the number of bites.

2. Bolus Action Insulin

These are the hormones used to replace the insulin that is produced after eating, to prevent glucose from rising too fast in the blood, and they are:

  • Rapid or regular insulin, such as Novolin R or Humulin R: mimics the insulin that is released when we eat, so it starts working in 30 minutes, working for about of 2h;
  • Ultra-rapid insulin, such as Humalog, Novorapid and Apidra: it is the insulin that has an almost immediate action to prevent food from increasing blood sugar levels too much, and should be applied right before eating.

These substances are applied to the fat tissue under the skin with the aid of a syringe or special pens for this function. In addition, one option is the use of an insulin pump, which is a small device that is attached to the body and can be programmed to deliver basal or bolus insulin according to each person's needs.

Learn more about insulin types, their properties and how to use them.

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