So I am going to being purchasing 100 U40 Insulin syrgines. I am gonna assume the U stands for units, so there will be 40 tics on the syringe. Its 1/2 a CC 29 guage half inch needle. Anyways I am going to want to inject 150-200 MCG twice a day into my shoulder. my question is how do i know when to stop pulling out the fluid and know i have the correct doseage? I used the calculator website and kinda got lost... bad with numbers.. so if anyone has knowledge or can help me out that would be splendid!