Like with all vitamins, you can't really tell the difference for a couple of weeks at least. Well, it's been about 3 weeks and what I'm seeing in myself is the feeling that I'm depleted. I can normally tell when I'm not getting enough of the vitamins and minerals I need from the look of my skin and hair. Both are looking better in the last 3 weeks. Considering I'm cutting out things in my diet all the time, this is filling in the gaps of what I'm missing.