I used both the roll-on and the deodorant everyday, twice a day.

Because my package came late, I was only able to complete 5 of the 7 days. With that being said, there is no visible difference from day1 to now. I do believe that the product is capable of reducing the appearance of dark underarm marks, but definitely not within 7 days. Consistent use over a longer period of time should give you better and more noticeable results.