Insulin – everything you need to know

The pancreas plays an important role in digestion and controls blood sugar regulation. This gland is hidden behind the stomach and spine, has a direct connection to the duodenum, and produces the hormone insulin in the beta cells. Insulin is the reason you can use glucose for energy. It helps your body unlock the door to the cells, allowing glucose to be absorbed from the blood.
You may wonder how the digestion process of carbohydrates goes.

  • What is always forgotten is that digestion begins in the mouth. Food is mixed with our saliva through chewing, which contains enzymes that initiate digestion. It cannot be said enough, always chew well.
  • Once the food pulp has arrived in the digestive system, the digestion of nutrients begins. A distinction is made between macro and micronutrients, such as secondary plant compounds. Macronutrients include fats, proteins, and carbohydrates. The glucose produced is released into the bloodstream via the mucous membrane of the small intestine.
  • The hormone insulin is produced in the pancreas, fed into the bloodstream, and instructs the body’s cells to absorb the glucose from the blood.

The hormone insulin is an important part of blood sugar regulation. One job, as mentioned, is to move sugar out of the blood and into the cells. Most cells in the body can only absorb energy this way. Energy is important for movement, and any other kind of body activity, as well as elementary things like breathing, brain activity, and of course as a drive for our heart, one of the most powerful muscles of our body.

Insulin’s other tasks include regulating the fat and protein balance.

A normal day for your blood sugar level

Depending on what we eat, the blood glucose level rises slowly or quickly; between meals, the blood glucose level can drop. Depending on what we eat during the day, a real roller coaster develops due to the fluctuations in the blood.

Insulin to control diabetes

All types of diabetes may require insulin to be delivered to the body in other ways. Ideally, your body produces its own insulin in sufficient amounts.
Type 1 diabetics cannot produce their own insulin and rely on insulin injections to keep their blood sugar levels under control.
For many people with type 2 diabetes, lifestyle adjustments and oral medications are sufficient to keep blood glucose levels under control. If again, this is not enough, additional insulin can be added to help regulate blood glucose levels.

How should you store insulin?

Insulin, like food, has a limited shelf life. Insulin that you do not use should be stored in the refrigerator.
Cold insulin injections, on the other hand, can be uncomfortable to inject. For this reason, it is recommended to warm up the insulin before use, simply place it on the countertop for a few minutes, but protect it from direct sunlight or other heat exposure. Insulin can be stored at room temperature for up to one month.
Insulin should never be stored in the freezer, and the expiration date should always be checked before use.

Insulin come in a variety of types.

They are classified according to how long it takes for the insulin to take effect in the human body, this is equivalent to the EFFECTIVE TIME. Both fast-acting and long-acting insulin help control blood glucose levels after meals. Each person has an individual need, and so the combinations they require are also different.

You can find an overview of the available insulin variants here:

Type of insulinOnset of actionMaximum effectDuration of effect
Very fast and rapid5-20 min20-30 min3 to 5 hrs.
Short-acting30-60 min2-4 hrs.5-8 hrs.
Intermediate1-2 hrs.4-6 hrs.up to 18 hrs.
Long-acting1-4 hrs.not definableup to 24 (42) hrs.

Each of the five insulins, from rapid-acting to long-acting, has its own unique characteristics. There are three key figures for all types, the onset of action, the maximum onset of action, and the duration of action.

  • “EFFECTIVENESS” time period until the insulin kicks in.
  • “EFFECTIVE MAXIMUM” Period of time until the maximum effect is developed.
  • “EFFECTIVE DURATION” Time period during which the insulin is detectable in the blood.

Some insulin is clear, while others look cloudy or blurry. Check with your pharmacist to make sure the type of insulin you are using is clear.
A cloudy insulin pen or vial needs to be gently massaged between your palms before injecting to make sure the insulin is evenly mixed (until it looks milky).

There are several methods of administering insulin.

All insulin has the same effect on the body. The long-acting ones, in particular, mimic the normal fluctuations of insulin levels in the body throughout the day. Different insulin has different characteristics in terms of how quickly and how long they are effective in the body.
Which insulin is recommended for you will depend on a number of factors, including:

  • Your age,
  • Your activity level,
  • your metabolism
  • your absorption time
  • and the length of time you want the insulin to be active in your body.

Dosage and therapy

A syringe, insulin pen, or insulin pump are the most common methods of administering insulin. The type of insulin injection you choose depends on your personal preferences, health needs, and health insurance.

In order to most effectively treat the individual needs of people suffering from diabetes, various forms of therapy have been developed in recent decades.

  • Conventional insulin therapy (CT) – based on the administration of mixed insulin.
  • Intensified conventional insulin therapy (ICT) – based on the basic bolus concept
  • Functional insulin therapy (FIT) – based on the basic bolus concept with the aim of enabling greater independence for diabetics
  • Supplemental insulin therapy (SIT) – based on the administration of antidiabetic medication (tablets) and a fast-acting insulin with meals
  • Basal insulin-assisted oral therapy (BOT) – based on the administration of antidiabetics (tablets) and a long-acting insulin
  • Basal insulin-assisted oral therapy plus (BOTplus)
  • Basal insulin-assisted incretin therapy (BIT) – based on a combination of GLP-1 with basal insulin
  • Continuous subcutaneous insulin infusion: pump therapy (CSII) – most advanced form but also most expensive

Your doctor will be happy to advise you on which type is the most promising for you and fits best into your daily life.

What is the best way to administer insulin by injection?

You can inject insulin into your body using either an insulin pen or a syringe. What’s best for you depends on your lifestyle habits and your doctor’s advice, so don’t be afraid to ask.

Infographic of insulin injection techniques: correct and incorrect injections depending on the length of the needle, insulin injection sites, and sequence.

Insulin syringes, what you need to know

  • They come in a variety of sizes.
  • The amount of insulin you need per dose is determined by your doctor.
  • Insulin is usually drawn into the syringe only when needed.
  • Compared to an insulin pen or pump, they are much more noticeable.

You should be aware of the different types of insulin pens and how they work.

  • Some insulin pens use pre-filled cartridges.
  • Others use pre-filled pens that are discarded when the medication is used up.
  • The needles in pens are usually smaller than those in syringes.
  • A pen cannot be used for all types of insulin. Pens can be more expensive than syringes and may not be covered by insurance.

Your doctor or diabetes educator will tell you how to administer the syringes. Insulin can be injected into many different areas of the body, including the following:

  • Legs/thighs
  • Buttocks
  • Upper arm
  • Abdomen

If you have diabetes, your doctor may advise you to massage the area around the injection site. This will prevent the formation of lumps or unsightly fat deposits.

What is the alternative to insulin injection?

There are two methods that do not require a daily injection to deliver insulin.

Insulin pumps:


  • Insulin pumps are implanted in the fat layer under the skin and deliver insulin continuously.
  • they are usually implanted in the abdomen or the back of the upper arm.
  • they can deliver insulin more accurately than a syringe.


  • they can cause weight gain
  • they can cause infections
  • they can be costly

Insulin inhalers:


  • cause insulin to work quickly
  • are often given before a meal
  • must usually be used with injectable, longer-acting insulin


  • may cause less weight gain
  • may cause coughing
  • do not provide as accurate amounts compared to other methods
  • require routine monitoring for adverse effects

Ultimately, your doctor must decide which of these methods is best for you.

missing articles, tell us your question that moves you