i take 30 mg zinc a day. it decreased my acne by 50%. i am 100% clear by eliminating carbs from my diet. anyway. when i took 45mg i was also completely clear instead of only just 50% problem it caused me depression and lack of appetite. i got my friend to try zinc 50mg and now he is 60% clear. before he had so much acne and was considering taking accutane. the bottom line is you should try zinc chelated. that is what worked for me. but if you want to get rid of all your acne, i recomend cutting carbs out of your diet.