What Bio said is the easiest way to figure out how much IU's you're taking. Just take (content in vial)/(amount of BW) = (HGH concentration). If you have 10 iu's in the vial and you add 1ml or 1cc (they're the same) of BW, then you have 10iu/ml of HGH concentration. If you add 2ml of BW to the vial you have 10iu/2ml or 5iu/ml of HGH concentration, etc. If you get confused, just put the formula in an excel sheet and you're GTG. Good luck.