The bottle itself is a generous size and will last you a long time. I used it for about a week, and now my forehead is covered in tiny bumps and whiteheads. After a quick google search, I think I probably have fungal acne, or pityrosporum (malassezia) folliculitis. This product contains saccharomyces ferment (a yeast ferment) that can exacerbate fungal acne.  Be sure to do a patch test before using this product all over your face! If you know that you are sensitive to yeast ferments, I would steer clear of this.