Insulin pens with memory (using Sanofi penfills in Novo Nordisk pens)

For basal, I use prefilled Abasaglar pens, with a Timesulin cap. These caps are somewhat overpriced at $20 bucks, but worth it. They only remember last time of insulin injection, not dosage. For my basal insulin, this is fine, because I use only a single dosage every day.

For bolusing, I use Apidra. I need to know both the last time I took insulin, and the dose. For this, I use the Novo Nordisk echo pen. It is not supposed to be compatible with Sanofi insulin penfills, but the latter are easy to adjust so they fit a Novo Nordisk pen.

Novo Nordisk and Sanofi penfills differ in 3 ways: Novo Nordisk penfills 1) are very slightly thinner; 2) have an orange plastic cap; 3) are very slightly longer.

To make the Sanofi penfill into a Novo Nordisk one: 

1) Make the Sanofi penfill slightly thinner by peeling of the label.  

2) Twist off the orange plastic cap from a Novo Nordisk penfill, place it on the Apidra penfill.

3) Place a small ring in the Echo pen, at the back of the Sanofi penfill, to make up for the shorter length. I use a plastic colored ring from an Oral-B electric toothbrush head for this.

Beware: This DIY trick will lead to very very slight changes in how much insulin is administered for every (half) unit specified with the Echo. I am personally not worried about this, because the difference is so very slight. Also, I always use this approach, so in case my insulin sensitivity per unit of insulin administered in this manner starts to lessen, I can simply adjust carb/insuline and glucose/insulin ratios.

Apply at own risk!