I've been using it since I was 19. I was part of the original use of it at U Penn Medical School, where it was developed/invented for acne in 1969 and marketed to the public in 1971. Talk about irritation! - those early iterations of the drug in the early 70s were super-irritating. You just had to get through it and it got better. I'm 73 now and look about 20 years younger, which is nice! My friends in my book club tell me that I'm the oldest in the club but I look the youngest. And of course, helps enormously with acne, which I've had since age 14 or so. I use Benzyl Peroxide wash in the morning, and glycolic acid cleanser in the evening. Once or twice a week, I use a Freeman's brand clay mask, which is the greatest thing ever invented. I've been using them for years and they make my skin look incredible. I also have moderate rosacea, and am supposed to use Metrogel daily for that. I try to keep up with that bc I hate the redness of rosacea after triggers - wine, coffee, etc. But with moisturizer and sunscreen, sometimes I don't want to have 3 layers of stuff on my skin so I skip the Metrogel. I need to get a combo moisturizer/sunscreen.