This is a really strong product, and I would recommend that anyone who uses it follow the recommended procedure of starting out just twice a week, with a small amount dabbed onto a Q-tip. When I first started using this product, I would only leave it on for 10-15 minutes and then rinse it off. I didn't realize how strong it was until I noticed that the skin on my fingers was peeling off after a week of rubbing it onto my face. It is an expensive product, but you only need a really tiny amount, so a 50 mL bottle can last over 6 months. It's a strong exfoliant and dries out blemishes. I think the mandelic acid is an effective antibacterial as well. I believe it did fade discolorations in my skin after several weeks of continued use, but it might have simply been a result of the top layer of my skin sloughing off. Regardless of whether or not you have hyperpigmentation or scarring, regular exfoliation will be beneficial to improving skin brightness and clarity.
San Gabriel, CA