I'm 48 now I've been using Dan's products for about ten years now - the 2.5% Benzoyl Peroxide was especially helpful, and I still use it on and off to this day. I stumbled upon Dan's website after total exasperation and frustration at being a grown adult with acne. Why was this still haunting me from my teenage years? I'd get these large, deep, painful pimples, peppered around my forehead, neck and face, and smaller white pimples around my mouth and it drove me nuts. The 2.5% treatment helped out some, and I stuck to the regimen using Neutrogena Oil-Free Acne Cleanser. After about a year I wondered if allergies might be part of the problem, so I made an appointment with a local allergist and went through the full battery of testing. The doc dipped these racks of small cones into different liquids and pressed them onto my arms. My skin immediately reacted to just about all of the local flora, but I was also told that I had a dairy allergy, which was news to me. At the time I was eating lots of yogurt and salads sprinkled with gorgonzola or bleu cheese. I cut as much dairy out of my diet as possible (except the milk in my coffee - can't live without that!) and my skin improved drastically almost immediately. Since then, I wash my face with Purpose Gentle Cleansing Wash from Walmart and moisturize with Neutrogena Healthy Skin Anti-Wrinkle from Amazon and only occasionally need to use the 2.5%. It actually expires before I finish the travel size bottle. Just wanted to share this as something to look into for adults haunted by their teenage skin!