Pen needle reuse

So for those of you that reuse pen needles… What is the preferred method; capping the needle and unscrewing it off the pen? Or just putting the big cap on over the whole pen and leaving the needle attached to the pen? Or other ideas?

I put the tiny green cover back over the needle and the large pen cap over that. I think removing the needle and reinserting it offers more opportunity for contamination because the end of the needle that goes into the pen is not protected by the cap once the needle is off the pen.

i only do it when im out of needles and out and about. so i fish a used one out of my bag and stick it back on the pen. cant be the best method, the use of a used one from the depths of my bag but never had a problem. i dont think you are supposed to leave them attached to the pens.

I often leave them on the pen - without the tiny cover as recommended. The disadvantage is that the vial might fill with tiny air bubbles. It is possible to remove them but they can be overlooked. Air is compressible and this might influence the dosage. Another advantage of changing the needle every time is that you will not forget to prime. All of todays pens need to be primed before the next injection if they have been exposed to little g-forces from walking etc. This is due to mechanical design decisions that allow convenient back dialing. The older pens like the NovoPen3 did not have this problem.

I put the green cap on and that is it- it stays on the pen until I switch needles. The larger cap won't fit under the pen tops. I only prime the needle when I start a new cartridge- I have a novo pen junior and echo now. I will have two echos if I ever get to my endo's office to pick up the second one.

ive got a novo junior too and i looove it! viva half units!!!

I remove the pen needle from the pen and put the clear cap on it and put it on my night stand until I need it again. This is probably my worst diabetic habit? But I don't leave the pen needle on the pen because that's not good for the insulin pen.

Would highly recommend simply not reusing:

wow! that is crazy!

This picture gets thrown around on the net now and then and is likely inaccurate with regard to the pen needles most of us use. There was quite a discussion of it on Reddit and one guy did his own experiment:

The original source for the photos appears to be BD (needle manufacturer) and they've been used a lot for IV drug needle exchange programs. Example:

With photo credit to BD.

I don't put the green cap back on. I occasionally remove air bubbles from the cartridge (point up and "shoot" till air is gone). I reuse pen needles...use reuse 5 or 6 times. I also reuse syringes for use with vial lantus. Every 1st monday of the month, I put 7 new syringes in a container(#1) in the fridge along with my Lantus vial. I use one syringe/day of the week, and each day I place the used syringe in a 2nd container in the fridge. End of sunday, I have 7 used syringes in container#2. Monday, I put all used syringes in Container#1 and start the week over again. I basically refrigerate the syringes and use each syringe approx 4 times in a month. I've been using this method for 10+ years. It saves money, and helps remind me/indicates whether or not I took my injection.

I also keep the Humalog pen attached to the meter case. I use two separate I keep in my purse, and one I keep on the dining room table. Having two "stations" helps me remember to inject...and since doing this, my A1c has fallen to 7 (from 7.6) in 3 months. I think it will help me get it down a bit further as time goes on.

So to take this one step further— how about swapping the same pen needle between two different pens-- in my case lantus and novolog. I know the two generally shouldn’t be mixed but could this near infinitesimally small amount of cross contamination really matter? I’d love to hear from a real chemist on this one as well as everyone here

My idea is to at least prime well enough that you dont give yourself the needle of lantus plus the novolog you wanted, if you know what i mean.
for me it would just be inconvenient to swab needles out, but i dont think it is extremely dangerous.

That picture rings true for my experience.

I find that they're good for 3-4 injections before starting to really get noticeable when inserting.

I find that first insertion is very comfortable and painless; each subsequent insertion gets a little more "aware". By the 5th, it's obviously getting dull.

Which must mean I have the hide of a Rhinocerous.

Judging by how much comes out when priming just a single unit, I'd say this is no concern at all. Any residual will be flushed out pretty thoroughly when you prime it.

My NP told me to take the needle off every time and to leave it off until the next use. That seems counterintuitive because her reason was to leave the pen with a "closed system." It sounds like most people don't do this. It seems like any problem with technique would show up soon in the BG readings. I just leave the needle on and reuse it until it no longer feels sharp. This seems to work fine.

I think the reason why you should take a needle off the pen is because every time you leave it on, air goes into the vial. you can see this, when you start a new vial, there isnt any air in it, and during the use, a small air bubble starts to grow and grow, until the vial is used up.
i believe this bubble exists because air can enter through the needle while the pen is not at use.