I have done my research on the amounts of everything on this and they are all safe, they are for sure at the very upper limits of especially the highest percentage ones but most of these vitamins are water-soluble so it's impossible to overdose on those as you just pee them out! Anyway, on to the product. I have used these supplements on two separate occasions this past year. It's been two times because the first time, after just two months, I was so happy with the change in my skin that I figured I was cured! Recently though I had a horrific volcanic explosion on my chin, jawline, and upper lip because I was trying out the OCM (didn't work for me!). Out of desperation to cure my skin I went out and bought this stuff again, two weeks later my dozen or so pimples from this adverse reaction have cleared up, and I haven't had any new eruptions since! This stuff is not cheap but so worth it for me, I do take the four pills a day (religiously, might I add -- after breakfast & after dinner). My acne (besides the reaction to OCM) is hormonal as I have PCOS. My medication for PCOS hasn't done much for my acne and I believe this supplement corrects what that can't (I've read that there are issues with absorption of various vitamins when you have PCOS, mainly vitamin B, and that an extra amount of vitamins/minerals are needed to help counteract the effects of the hormonal imbalance). Anyway, this is just one of those things you've got to try, especially if you have hormonal acne like I do, nothing has helped it the way these supplements in conjunction to good skincare has!