Where and how to apply insulin with a syringe or pen: step-by-step

Insulin can be applied with a syringe or a pre-filled pen, however, the syringe remains the most common and cheapest method. In either case, insulin must be injected into the fat layer under the skin, where it will be absorbed slowly, imitating the production of the substance by the pancreas.

In addition, insulin can also be introduced into the body by an insulin pump, which is a small, portable electronic device that releases insulin for 24 hours. Read more about how the insulin pump works.

1. Apply insulin with a syringe

There are several sizes of insulin syringes, ranging from 0.3 to 2 ml capacities, depending on the range of insulin units a person needs to make.

Generally, each ml can be divided into 100 units, but there are insulins that have 500 units in each ml and, therefore, the calculation of the necessary units should always be explained by the doctor, according to the type of insulin and the blood glucose values.. Once you know the amount to inject, you should:

1. Wash your hands to avoid dirtying the insulin vial or transporting bacteria to the syringe; Place a sterile needle in a sterile insulin syringe; Disinfect the rubber in the insulin vial by wiping a piece of cotton wool moistened with alcohol; Insert the syringe needle into the rubber of the insulin vial and turn the vial upside down so that the needle is immersed in liquid and does not suck in air; Pull the syringe plunger until it is filled with the correct number of units. Normally, the syringe is divided with several risks that mean 1 unit and is marked every 10 units, to facilitate the task; Remove the needle and syringe, capping the bottle again, if possible; Make a fold in the skin, using the thumb and forefinger; Insert the needle completely into the fold, at an angle of 450 to 90º, with a quick and firm movement; Push the syringe plunger until all the contents are released; Wait for about 10 seconds and remove the skin needle, releasing the skin fold after removing the needle.

When it is necessary to mix 2 types of insulin in the same syringe, you must place the fast-acting insulin in the syringe and only then add the slow-acting insulin, without having to change the needle. Normally, fast insulin is transparent and slow insulin is whitish, similar to milk. Both insulins should be mixed before aspirating into the syringe, it is recommended to roll the vials between both hands instead of shaking.

After application, the needle and syringe must be thrown in the trash or stored in a proper container so that they can then be delivered to the pharmacy and recycled. Whenever possible, the needle should be protected with the cap. No syringe or needle should be used in more than one application, as it may increase the risk of infection or reduce the action of the medication.

2. Apply insulin with a pen

The pen is a more practical option than the syringe, however it is more expensive and, therefore, may not be used in all cases. To correctly apply insulin using a pen, it is necessary to:

1. Wash your hands and have the injection site clean, and if it is dirty, you may need to clean the site with an alcohol swab or gauze; Gather all the necessary material, which includes a pen prepared with the insulin cartridge and needle and compress; Prepare the amount of insulin to apply by turning the pen and looking at the number on the display. For example, if your doctor has indicated that you should take 4 units at dinner, you must rotate the pen until the number 4 appears; Make a fold in the skin using only the thumb and index fingers, mainly in the belly and thigh; Insert the needle, between 45º to 90º, with a quick and firm movement. As the needle is very small and is only inserted into the skin, it causes the sensation of a mosquito bite, not being painful, and a larger angle (90º) should be made the more body fat the person has; Push the plunger or button all the way to inject the insulin; Wait up to 10 seconds before removing the needle from the skin, for the liquid to fully enter the body; Loosen the small fold of skin.

Normally, the application of insulin does not cause pain or cause changes in the skin, however, shortly after the application of insulin, a small drop of blood can come out, not being a concern, and can be cleaned with a compress.

Where to apply insulin

Insulin can be applied to the belly, thigh, arm and butt and is usually taken before eating, such as breakfast, lunch or dinner.

Places where insulin can be applied

The application on the belly and thigh allows a skin fold to be made, but on the arm, the application can be done without a fold when it is performed by the person himself, because the movement is more complicated.

Its application must always be carried out in different places, each time, to avoid the accumulation of fat and to make the skin flabby in the region, scientifically called lipodystrophy. Read more at: Complication of incorrect use of insulin.

How to prepare the insulin pen

There are disposable insulin pens, which means that once the amount of medicine inside the pen is finished, it must be thrown in the trash and therefore they do not need to be prepared, just turning the pen button up to the desired amount of insulin.

However, most pens need to be prepared as soon as an insulin cartridge is finished, as they can be used over several years and, therefore, it is necessary to:

1. Disassemble the pen by turning; Remove the empty insulin tank and insert a new vial into it; Join the two parts of the pen together; Attach a needle to the end of the pen; Test the function and see if a small drop of insulin comes out and remove any air bubbles that may be inside the bottle.

After the pen is assembled, the patient can use it until the product is finished, however, it is advisable to change the needle daily, so as not to hurt the skin or cause infections.