I have been using this for awhile now, and purposely waited a month or better to review this product to give a more accurate review. I really like this product. I had, up until this point, never used a chemical peel; so I was more than a little nervous about jumping into this sort of thing. Skin background, I had acne from pretty much age 12 and up. I'm 26 now, and for awhile my skin had gotten much better...around the 16 mark it started to slightly improve and by 20-something it wasn't a huge problem. I still had issues with some things (most moisturizers broke me out, I couldn't wear lipstick...ever. or...stains..or any kind. literally just if it went on your lips it broke me out.) but, for the most part, it was mostly handled. Then I had surgery at the end of last year, was on antibiotics for awhile, and on bed rest for a month or so while healing. My skin went stupid. I went from maybe one or two small zits occasionally (with hyperpigmentation) to all of a sudden 5-7 every few days. My entire chin was red, everything was just horrible and terrible. I had no idea what was causing it, medication, surgery, reactions, whatever. I tried cutting out various foods for awhile at a time, nothing helped. Cutting out sugar, caffeine, wheat, meat (at different times of course) - literally nothing made any difference whatsoever. So, last hope, I buy this. Again, chemical peels were the one things i hadn't tried before. So. This. It works so bloody good, man. I really can't say enough. This, plus taking fish oil omega 3's, has made a drastic shift in my skin. I am still oily, I feel I may be oily to the day I die, but as of right now I have 0 active zits on my face. Over say a week period (even DURING PMS) I've had a reduction of severity of about 98%. I can wear lipsticks and lipstains a lot easier with less problems, scars fade faster, pimples I do get last shorter. I'm in the camp that rarely if ever gets black heads, I always get kinds with whiteheads and it sucks - but this makes it suck a lot less. Other positive things, I HATE fake fragrance in things. I just hate it. This has none, and yes, it smells a tiny bit, but not terrible and it fades quickly. I have such oily skin, I put this AHA on twice a day, every day, and my skin actually feels softer after. It does not dry out my skin whatsoever, it does not make it more sensitive. If you have dry skin, you know, be careful about it, but for me ~oily mcoilslick~ it works great. If you have whiteheads, if you have oily skin, if you have sensitive skin, if you have hormonal acne, if you have acne that leaves you scratching your head because all of a sudden it decided to rain down upon your face like armageddon blasting down upon the once great planet - BUY THIS (and, also, maybe, try taking at least 500mg of omega 3s? omega 3s from fish oil specifically works well for me. primrose oil and flax and things like that haven't helped as much, but fish oil did. so, you know, just a mild suggestion to try out if you haven't already.) I have not been paid or compensated in any way for my review of this product, I did not receive the product free or for any sort fo discount - but, hey Cosrx, I will definitely do so if you send me more things because I am officially a fan..