@researchcat @paradox Good points, I have a habit of pushing 1iu before I mount the needle, which essentially primes the needle upon insertion. I mean, yes, it’s Snake Logic, but seems to work.
I usually just write on a label a concentration in mcg/units. For example, if I reconstitute 10mg (10,000mcg) in 2 ml (2,000u) I put "x50". It is very useful, for example if I need 500mcg (0.5mg) I use 10 units since 10x50=500.