you will use the whole bottle [SEP] if you are going for a true platinum finish and you have not obtained it yet there is some things you need to know this bottle advertises that you will be able to obtain a platinum look with it but i am skeptical i followed all the instructions carefully after bleaching twice i obtained the lightness i was looking for but still had the brass naturally i rested my hair and hydrated it two days later i applied this product to wet hair with gloves and rinsed after minutes per instructions no results i went right back in and reapplied for minutes lighter but still lots of brass using it the next time i shampooed i left in for ten minutes lighter but still brassy see pictures i will end up going through this entire bottle i think and do not know if i will be able to get the true ash white i am looking forthe scent is not offensive to me but is a very strong orange scent which is almost house cleaner ish instead of beauty product ish shrug not a deal breakerthe upside to this product instead of the t wella is that it is easier on your hair mine has no dryness after using multiple times however all told i am sure i will be going back to wella just too much effort to lift the brass from my hair i like the one and done method