Insulin administration device
The device used to inject insulin should also be checked to ensure that it is able to deliver insulin properly. Sometimes, insulin pens can become jammed or insulin cartridges can crack and leak, both resulting in reduced insulin delivery.

The insulin needle used should be of the appropriate size (usually 4-6mm) and should also be changed after each use and disposed of safely in an appropriate disposal bin. Repeated use of the same needle can make insulin delivery less effective, as the needle becomes bent, blunt and can make injecting painful.