Used the stuff 13 years ago when I was 16. After a 3 month course the doctor had a look and said that the acne hadn't completely gone away so I went on for another 3 months. After the last course I took I have never had any acne. The stuff is excellent but it does dry up your skin. I also felt in made my hair more curly as it was straighter before. Anyway, I would take it again if I had to. It's the only fast and effective way.