Insulin is a protein consisting of amino acids divided into two chains. For a human, insulin is divided into A and B chains, with 21 and 30 amino acids respectively. The chains are linked by two specific chemical bonds called disulfide bridges. The A chain also contains an internal disulfide bridge.
In insulin derivatives, the structure of insulin has been modified either by changing the place of amino acids, replacing one more amino acids with another amino acid, adding or removing amino acids or adding a part to insulin that changes its effect, such as a fatty acid chain.
Depending on the modification, different insulin products have a specific action and duration in accordance with the dose.
Insulin products can be divided on different grounds:
Based on the duration of action to rapid-, regular or short-, intermediate- and long-acting products
Based on the chemical structure and manufacturing method to human insulin, animal insulin and insulin derivatives. In Finland, the use of animal-sourced insulin is rare.
Based on the principle of use to basal and mealtime insulins
Biosimilar insulins are copies of insulin products that have been previously granted a sales permit and have proven properties, efficacy and safety. According to the Decree on Medicines, a doctor should prescribe the most affordable exchangeable insulin product, whether original or biosimilar.
Know your insulin
In addition to the product’s properties, there are individual differences in the absorption and action of insulin products. Contributing factors include the injection site, circulation, potential swelling or calluses on the site, temperature of insulin, ambient temperature, injection technique and amount of body fat.
The person with diabetes must be familiar with the mode and duration of action of the insulin product they are using as well as the dosing principles. In the medicine index of Terveyskirjasto, you can search for the insulin products you use based on the brand name. The insulin products and dosing equipment used in Finland are listed on the Finnish Diabetes Association’s website.