First off I appreciate any comments that will help I am a new member and would love your input .I got some humatroph in the cartiridge .i don't have the pen but can extract out of the cartridge. My goal is to do three Iu's day . My question is since there is 72 Ius in the cartridge extracting three is very difficult and not accurate .is there any recommendations that anyone has .I was thinking of putting it into an empty bastatic water container and doubling the Amount of water in the vile to be able to extract more and just double the IU amount if that makes sense