Dr Aidin Rawshani

Types of insulin and how they are used to treat diabetes


Different varieties of insulin: differences, similarities and use

In the previous chapter discussed what insulin is and what effects insulin has on the body. In this chapter, we will explain what types of insulin are used to treat diabetes. As previously explained, insulin is a hormone that regulates blood sugar, as well as the circulation of fat and protein in the body.

People with type 1 diabetes do not have their own production of insulin because their immune system has attacked and destroyed the cells of the pancreas (beta cells) that make insulin. Therefore, people with type 1 diabetes must supply insulin with syringes or by pump.

People with type 2 diabetes actually have their own insulin (at least the first few years of the disease) but the insulin is less effective in the body and therefore more insulin is needed to control blood sugar. Therefore, many people with type 2 diabetes need to supply insulin (especially after many years of illness because their own production of insulin decreases even in type 2 diabetes).

Insulin is vital for those who have type 1 diabetes. People with type 2 diabetes usually do without insulin in the first few years, but they may need insulin after a few years to control their blood sugar.

Regardless of the type of diabetes you have, the effect of insulin is the same. Insulin leads to a drop in blood sugar because the insulin signals to the cells of the body to take up sugar (glucose) and use it as a fuel. You can read about the effects of insulin in previous chapters.

Why is insulin needed if you have diabetes?

People with type 1 diabetes do not have their own production of insulin and therefore depend entirely on receiving insulin via a syringe or pump. If you have type 1 diabetes and don’t get your insulin, your blood sugar rises. It can rise so much that you develop the condition of ketoacidosis and eventually become unconscious and at worst you can die. Before 1921, there was no insulin, and then all people who had type 1 diabetes died. Today, research has come a long way and in a few years, perhaps, we will be able to cure the disease. In the meantime, we can welcome the fact that people with type 1 diabetes can now reach old age, although life expectancy is still 11 years shorter than those without type 1 diabetes.

People with type 2 diabetes need insulin to better regulate their blood sugar. This is because people with type 2 diabetes have a worse effect of insulin: they say that the body is “resistant” to insulin and this is called insulin resistance. After many years of type 2 diabetes, the pancreas may become exhausted and the production of insulin may decrease. These two factors, namely insulin resistance and subsequently reduced production of insulin, cause blood sugar. In this case, you need to inject more insulin using a syringe to control blood sugar.

Insulin as a medicine

Today, insulin is available as a medicine. There are both insulin pens and insulin pumps that are easy to handle. The insulin is manufactured using advanced methods, which involve using bacteria to make human insulin for us (see previous chapter). Today we have learned to make exact copies of human insulin (human insulin) and we have also learned to make variants of human insulin (insulin analogues). These variants, i.e. insulin analogues, may have slower or faster effect than insulin and may be desirable in many cases. For example, when eating a meal, it may be useful to use fast-acting insulin (“fast-acting insulin”) to prevent blood sugar from getting too high after the meal.

Thus, there are the following variants of insulin:

  • Human insulin (also called human insulin) – an exact copy of human insulin.
  • Insulin analog (also called analoginsulin) – chemically modified insulin that has other properties than the human variant.

Patients often receive several variants of insulin as this allows better control of blood sugar. One often speaks of the following insulin variants:

  1. Mealtime-insulin
  2. Basal-insulin
  3. Mix-insulin

Mealtime insulin: insulin taken with a meal

This is used to lower blood sugar associated with eating food. There are two types of mealtime insulin, namely direct-acting and fast-acting.

  • Direct-acting insulin is an insulin analogue and has a very fast effect. The effect lasts for 3-5 hours but is greatest between 1-3 hours after injection. You take direct acting insulin in conjunction with the meal. Examples of direct acting insulin are: Humalog® (insulin lispro), Novo Rapid® (insulin aspart) and Apidra® (insulin glulisine).
  • Rapid acting insulin is human insulin and begins to act within 30 minutes after injection. The effect is strongest after 1-4 hours and lasts up to 8 hours. You take fast-acting insulin 30 minutes before the meal. This means that you have to have foresight, which can be difficult. Therefore, fast-acting insulin is increasingly used today. Examples of fast-acting insulin are: Actrapid® (human insulin), Humulin Regular® (human insulin), and Insuman Rapid® (human insulin).

The more carbohydrate the food contains, the more insulin must be taken in conjunction with meals. If you take too much a dose, your blood sugar is too low and if you take too high a dose, your blood sugar becomes too high.

Base insulin

Base insulin is used to obtain a prolonged decrease in blood sugar. It is insulin with a very long action, thus reducing blood sugar over a long period of time. There are two variants of basic insulin, namely medium-acting and long-acting.

Medium acting insulin (Protamin+ human insulin) acts between 14 and 24 hours. The effect starts within 2 hours and is strongest after 4 to 12 hours. Examples of basal insulin are: Humulin NPH®, Insulatard® and Insuman®. The reason for achieving such a long effect of human insulin is the binding of the insulin to protamine, which causes the insulin to be released more slowly from the site where it is injected.

Long-acting insulin (an insulin analogue) begins to act after about 90 minutes and the effect is most pronounced between 3-16 hours and lasts up to 24 hours. Examples of long-acting insulin are: Levemir® (insulin detemir), Lantus® (insulin glargine).

Mixed insulin

Mixinsulin is a mixture of meal insulin and basal insulin. It uses an intermediate action and direct-acting insulin. Examples of Mixinsulin are: Humalog® Mix25 and Humalog® Mix50 and NovoMix®.

How to take his insulin: injection of insulin

Taking your insulin can be difficult for people with diabetes, especially when the disease is new. Injection of insulin can be socially stigmatising and affect social activities and routines. This is, of course, very regrettable because people with diabetes should be able to take their insulin without any consideration of social circumstances and requirements.

Insulin is usually injected with pens, although pumps (insulin pump) are becoming more common. If you use an insulin pen, you take out the pen when it is time to inject. If you use a pump, you always have a small device (the pump itself) connected to the body. The pump has a plastic tube that is attached to the skin via a cannula. With pump, one can get a smooth and slow injection of insulin. Today’s pumps are sophisticated and can be very comfortable and efficient.

You cannot eat insulin because it is a hormone and therefore it is broken down by enzymes in the intestine, and the insulin becomes inactivated. Therefore, insulin must be injected directly into the body. Insulin is injected into the subcutaneous fat. Insulin is not injected into the blood as this would lead to overdose and fall in blood sugar (only a doctor and nurse can inject insulin directly into the blood). When insulin is injected into the subcutaneous fat, it takes a while before it reaches the bloodstream.

The insulin is usually injected into the subcutaneous fat on the stomach, but the outside of the shoulder and the buttocks also go well. The skin is always lifted up so a skin fold is formed because you are sure that the insulin gets into the fat and not into a muscle.

The needle should be kept for a few seconds (at least 5) to ensure that the full dose has been injected. It is good to vary the injection site so that you do not always stick at the same site, as insulin may affect the tissue where you inject it. (You can get something called “lipodystrophy” if you inject insulin into the same place always). Therefore, try to vary the injection site.


List of different insulins available

Table 1: Types of insulin

Type of insulinProductManufacturersInsulinPreparation
Fast-acting analogues
ApidraSanofianalogues insulinBottle & Ampoule
ApidraSanofianalogues insulinPre-filled penn
HumalogLillyanalogues insulinBottle & Ampoule
HumalogLillyanalogues insulinPre-filled penn
NovorapidNovo Nordiskanalogues insulinBottle
Novorapid PenfillNovo Nordiskanalogues insulinAmpoule
Novorapid NovoletNovo Nordiskanalogues insulinPre-filled penn
LONG-ACTING analogues
LantusSanofianalogues insulinBottle, Ampoule & Pre-filled penn
LevemirNovo Nordisk analogues insulinAmpoule & Pre-filled penn
TresibaNovo Nordisk analogues insulinAmpoule & Pre-filled penn
Human ActrapidNovo NordiskHumanBottle
Actrapid Pen*Novo NordiskHumanPre-filled penn
Actrapid Penfill*Novo NordiskHumanAmpoule
Human Velosulin*Novo NordiskHumanBottle
Humaject S*LillyHumanPre-filled penn
Humulin SLillyHumanBottle & Ampoule
Insuman RapidAventis PharmaHumanBottle & Ampoule
Insuman Rapid Opti SetAventis PharmaHumanPre-filled penn
Humulin ILillyhumanBottle & Ampoule
Humulin LenteLillyhumanBottle
Humulin ZNLillyhumanBottle
Human InsulatardNovo NordiskhumanBottle
Insulatard PenfillNovo NordiskhumanAmpoule
Human Insulatard Pen*Novo NordiskhumanPre-filled penn
Human Monotard*Novo NordiskhumanBottle
Human Ultratard*Novo NordiskhumanBottle
Insuman BasalAventis PharmahumanBottle & Ampoule
Insuman Basal OptiSetAventis Pharma humanPre-filled penn
MIXINSULIN analogues
Humalog Mix25LillyAnaloginsulinAmpoule
Humalog Mix25LillyanaloginsulinPre-filled penn
Humalog Mix50LillyanaloginsulinPre-filled penn
NovoMix 30 Novo NordiskanaloginsulinPre-filled penn & ampull
Humaject M3LillyhumanPre-filled penn
Humulin M2LillyhumanAmpoule
Humulin M3LillyhumanBottle & Ampoule
Humulin M5LillyhumanBottle
Human Mixtard 30**Novo Nordiskhumant insulinBottle
Human Mixtard 50Novo NordiskhumanBottle
Human Mixtard 10 PenNovo NordiskhumanPre-filled penn
Human Mixtard 20 PenNovo NordiskhumanPre-filled penn
Human Mixtard 40 PenNovo NordiskhumanPre-filled penn
Human Mixtard 50 PenNovo NordiskhumanPre-filled penn
Mixtard 10 PenfillNovo NordiskhumanAmpoule
Mixtard 20 PenfillNovo NordiskhumanAmpoule
Mixtard 30 Penfill**Novo Nordiskhumant insulinAmpoule
Mixtard 40 PenfillNovo NordiskhumanAmpoule
Mixtard 50 PenfillNovo NordiskhumanAmpoule
Insuman Comb 15Aventis Pharma humanBottle & Ampoule
Insuman Comb 15 OptiSetAventis PharmahumanPre-filled penn
Insuman Comb 25Aventis PharmahumanBottle & Ampoule
Insuman Comb 25 OptiSetAventis Pharma human Pre-filled penn
Insuman Comb 50Aventis PharmahumanBottle & Ampoule
Insuman Comb 50 OptiSetAventis PharmahumanPre-filled penn

How much is 1 E (unit) insulin?

Most medicines in Sweden are measured in milligrams or grams, but not insulin. Insulin is measured instead in units (E). The above photo shows an insulin grade of 100 IU/ml. IE is given international units and this unit is a measure of the biological activity of the drug. This device is also used for other medicines such as heparin and various vitamins. IU thus indicates the biological effect of the drug, and in this case the biological effect is how much blood sugar is lowered by each millilitre of medicine.

1 unit Lantus lowers blood sugar as much as 1 unit Humalog but the difference is that Lantus reduces sugar while Humalog gives a quick decrease.

How much insulin do you need?

This is a question you and your doctor/nurse need to discuss because there are large variations between patients. This is because we display different sensitivities to insulin and we also eat different amounts of carbohydrates. You should discuss this issue with your doctor/nurse as it is extremely important that your insulin dosage is as accurate as possible.

More about insulin

  • What is insulin and what effect does it have in the body?
  • Types of insulin and how they are used (injected)
  • Overdose of Insulin sensitivity
  • Side effects of Insulin
  • How to handle Insulin
  • Insulin Pump
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