Science: Why changing needles is so important in diabetes management

Changing your needles will reduce your likelihood of infection and reduce injection pain, and it's crucial.

Re-using your needle increases your risk of infection significantly.

The last thing you need is an infection. Diabetes management is hard enough already. Unfortunately, people with diabetes are much more likely to get a skin infection than non-diabetics.

We're constantly creating opportunities for bacteria to get under our skin because we inject things so frequently. Freestyle Libre applicators, Dexcom inserters, and Novopen tips are fantastic vehicles for bacteria to hitch a ride on. Think of a Novopen tip as a one-way train ticket to your interstitial fluid for a gang of microbes.

Above is an image of a needle that has been used once and pulled out, taken using scanning electron microscopy (SEM). The orange bits are bacterial cells. When the needle touches your skin, it also touches bacteria on your skin. Generally, a new needle is so fine-tipped it goes in without much issue and comes out okay. 

But when it comes out, it's dragging along the hole it has just created and acquiring bacterial hitchhikers.

When you use this needle again, it's pre-loaded with pathogens, and they've multiplied on your needle tip. So when you inject that next shot of insulin, you're also going to deliver these microbial stowaways directly into your body. From a microbes' perspective, this is a reliable and easy way to get inside their next host - great!

Every time you re-use your needle, you add to the microbial population on the tip. Even if you sterilize your injection site with an alcohol wipe beforehand, you won't be protected. It doesn't matter how clean your skin is when you're inserting bacteria into your body yourself.

Changing your needles will reduce injection pain.

Above is an image showing the tip of a needle after multiple uses, and you cannot see this with the naked eye - do not tell yourself that yours "is fine" because it's not.

Ever notice how re-using the needle gets more and more painful? Well, this is why. As far as a skin cell is concerned, you're trying to inject insulin with a tree trunk.

As the tip bends, you're also building a bacterial scoop. This shape will come into contact with many more microbes, and your risk of infection will go up with each re-use.

Change your needle!

So, it's pretty clear that you should be changing your needle every single time. And you need to be cleaning your injection or insertion site every single time. You need to use something with anti-microbial activity to get the best results, like alcohol wipes.

Unfortunately, this is just impossible for some people. We live in a world where we all suffer from similar diabetes, but none of us have access to equal care. Many people with diabetes cannot afford to use this many needles, and we all have our own circumstances.

So don't feel bad if you can't change your needle, but do feel better about spending money on needles instead of something else you might not necessarily need. You're looking out for yourself, and that's important. For some people, the risks of re-using needles are not as significant as other problems in their lives, and that's okay. They are looking after the sum total of their health and being, and that's the end goal.

We want you to be happier. We hope that this is a solution and that this knowledge helps you reduce your injection pain and reduce any anxiety around skin infections.

Now, do you clean your site? You can get leading skin site preparation wipes from us for just 10p here. Never worry about a skin infection from applying your Freestyle Libre, Dexcom, or Omnipod ever again.

Sources & References:

Abe, S., Haraga, I., Kiyomi, F. et al. Bacterial contamination upon the opening of injection needles. JA Clin Rep 4, 61 (2018). https://doi.org/10.1186/s40981-018-0197-7

Yutaka Kawakami, Takashi Tagami, Pumping infusions with a syringe may cause contamination of the fluid in the syringe, Scientific Reports, 10.1038/s41598-021-94740-1, 11, 1, (2021).

This article is for informative purposes only and should not be used and is not intended as medical advice. Consult your healthcare professional in all instances.