Forms of insulin delivery

Photo of insulin being injected
PantherMedia / Dmitry Lobanov

To be able to work, insulin has to enter the bloodstream. It can't be taken in the form of tablets or capsules because then the hormone would be broken down in the stomach. There are a number of ways to get insulin into the blood.

Insulin is usually injected into fat tissue underneath the skin (subcutaneously). From there it is gradually absorbed into the bloodstream and is carried around the body. The most common way to inject insulin is using insulin pens and insulin pumps. Not many people inject insulin with syringes.

The most suitable form of delivery will depend on a person's health situation and their personal preferences. Blood sugar control is sometimes better with pumps. But there is not enough good research to be able to say whether pumps have any long-term health benefits or drawbacks compared to syringes or insulin pens.

Insulin pens and syringes

Although many people have a problem with the idea of using a pen or syringe at first, it's relatively easy to do. Most people soon get used to it.

Insulin pens are easier to use than syringes. They are about the size of a large ballpoint pen. They contain insulin-filled cartridges that last about a week, depending on how much insulin is used. You can easily set the number of units you want to use. The insulin is then injected through a thin needle by pressing down a button. With a bit of practice, it is even possible to do things like inject insulin at a restaurant table without others noticing.

There are also disposable pens that are pre-filled with insulin and can be thrown away after use. Various refillable pens are available too. Insulin manufacturers often give these away for free. If you decide to keep a free pen, you will only be able to use the insulin produced by that manufacturer. Because the shape of the insulin cartridges and the way the needle is attached vary greatly between different pens, it's not possible to mix and match different manufacturers' pens and cartridges. So it can be worth looking at various pens and trying them out before making a final choice.

Only few people inject insulin using a disposable syringe. But, with a little practice, it hardly takes a minute: You prepare the vial, draw the insulin into the syringe and inject it. The needles belonging to syringes, insulin pens or pumps shouldn't simply be thrown away in the normal waste bin. But you can put them in special disposal containers that can be safely closed and then disposed of in the normal rubbish.

Insulin pumps

Insulin pumps are slightly bigger than a matchbox. Each pump consists of a reservoir filled with insulin, a battery and a small computer. To use the pump, you insert a special thin needle into a suitable area of skin, like you do when injecting insulin with a syringe or pen. The needle is then fixed in place using a sticky patch, and is attached to a thin tube () that leads to the pump. The needle can be left in the same place for one to two days. Then the needle and should be replaced and inserted somewhere else on the skin.

Insulin pumps have two main functions: On the one hand, they are programmed to cover your basic insulin needs (basal rate) by regularly delivering small amounts of short-acting insulin. On the other hand, you can deliver extra amounts of insulin (bolus insulin) at mealtimes, just like you can when using a syringe or insulin pen. Injecting insulin when needed helps to prevent strong blood sugar fluctuations.

Because the pumps have to be programmed, some knowledge is required. To use the pump properly, you also need to have experience with intensive insulin therapy, regular blood sugar monitoring and adjusting your insulin dose. People who use a pump have to be very familiar with their diabetes in order to avoid high and low blood sugar.

Pumps aren't necessarily the best option for everyone with diabetes. Many people prefer to inject insulin several times a day rather than using a pump. Not everyone feels comfortable having a needle in them and wearing a pump all the time.

Pump or pen?

Pumps are often used specifically for people who have major fluctuations in their blood sugar levels – for example, they may often have hypoglycemia (low blood sugar), or levels that regularly rise steeply in the early morning hours. Pumps are also suitable for people who want to be very flexible, for example because they are particularly physically active or don't have a regular daily routine. Women who are planning to get pregnant or are already pregnant often choose to use an insulin pump too.

Blood sugar control is somewhat more effective with pumps than it is with insulin pens or syringes. But there's no proof that this is associated with fewer episodes of low blood sugar during the day. The studies do, however, suggest that episodes of low blood sugar at night are less common when insulin pumps are used.

There is generally not enough research on the long-term health benefits or disadvantages of pumps compared with pens or syringes. Pumps probably don't offer a dramatic improvement in diabetes treatment. They are rather a useful alternative for people who have particular problems or preferences. People who use insulin pumps over long periods of time are generally satisfied with their pump. This is also true of parents whose children use an insulin pump. They feel that pumps give the whole family greater freedom in everyday life.

Other forms of insulin delivery

Other forms of insulin delivery are currently being developed and tested. These include jet injectors and special patches that deliver insulin that is absorbed through the skin. With jet injectors, a high-pressure jet of insulin is injected through the skin without using a needle.

Insulin can also be injected directly into a vein in emergencies, when an immediate effect is needed. This should only be done by a doctor.

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Benkhadra K, Alahdab F, Tamhane SU et al. Continuous subcutaneous insulin infusion versus multiple daily injections in individuals with type 1 diabetes: a systematic review and meta-analysis. Endocrine 2017; 55(1): 77-84.

Bode B, Shelmet J, Gooch B et al. Patient perception and use of an insulin injector/glucose monitor combined device. Diabetes Educ 2004; 30(2): 301-309.

Deutsche Diabetes Gesellschaft (DDG). S3-Leitlinie: Therapie des Typ-1-Diabetes. AWMF-Registernr.: 057-013. 2018.

Qin Y, Yang LH, Huang XL et al. Efficacy and Safety of Continuous Subcutaneous Insulin Infusion vs. Multiple Daily Injections on Type 1 Diabetes Children: A Meta-Analysis of Randomized Control Trials. J Clin Res Pediatr Endocrinol 2018; 10(4): 316-323.

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IQWiG health information is written with the aim of helping people understand the advantages and disadvantages of the main treatment options and health care services.

Because IQWiG is a German institute, some of the information provided here is specific to the German health care system. The suitability of any of the described options in an individual case can be determined by talking to a doctor. informedhealth.org can provide support for talks with doctors and other medical professionals, but cannot replace them. We do not offer individual consultations.

Our information is based on the results of good-quality studies. It is written by a team of health care professionals, scientists and editors, and reviewed by external experts. You can find a detailed description of how our health information is produced and updated in our methods.

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Updated on December 8, 2021
Next planned update: 2024

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Institute for Quality and Efficiency in Health Care (IQWiG, Germany)

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