Depends, sticking with your current 2.5mg pen or getting a new script for the 5mg one? With the 5mg pen, youd twist to click number 45 from zero rather than going the full way around to the 1 mark, which is a whole dose. Mark that spot with your sharpie. To verify, keep turning from there until you reach the 1 mark, that should add up to 15 more clicks since a full dose equals 60 total. Twist back to your 45 mark afterward and inject from there. Next time the mark will already be set, so just turn to it and stop, no counting required.