Second pass at: A pen that felt like it delivered nothing: diagnosing it afterwards

Second pass at: A pen that felt like it delivered nothing: diagnosing it afterwards — setting out what I have, and where I think it stops being reliable.

A question about technique rather than about dose.

I have been doing the same thing for 4 months and it works, and then I read one of the documentation pages here and realised I may have been reasoning from a misunderstanding the whole time. Nothing has gone wrong; I would just like to understand why it has not.

What I do, exactly, is described below. Please tell me which parts are load-bearing and which are superstition.

Dose counters: pens show the remaining number of doses. When the counter reaches zero, the pen is empty and cannot deliver more. Noting the counter before injection prevents running out unexpectedly.

Coming back to post #3, because the follow-up matters more than the original answer.

Visibility of the dose: some pens allow you to see the insulin remaining; others do not. Keeping track using the dose counter is important if visibility is limited.

Reusability: some pens are single-use (throw away after one injection). Others can be reused until empty. Confirm which type you have. Reusing a single-use pen is ineffective because the mechanism does not reset.

Off-label dosing with a pen: if you want to deliver a dose different from the pen's pre-set steps (e.g., halfway between two step doses), that is off-label use. Some pens allow it; others do not. Confirm before attempting.