I decided to try out mandelic acid to treat my acne problems after reading numerous success stories about it online. I was all hyped up on claims about it removing blackheads, tightening pores, exfoliating skin, and so on and so forth. I thought maybe, just maybe, this mandelic acid stuff would prove to be the end-all cure for my acne. A bit of research landed me on Mandelic Serum 10% by Nucelle, which excited me with its rave reviews. I quickly purchased it and incorporated it into my regimen. I substituted it for the benzoyl peroxide that had previously been my primary acne treatment. Well, I applied the mandelic acid religiously twice a day every day for two whole months, and saw absolutely no change in my skin. In fact, my skin got WORSE. At first I gave it the benefit of the doubt and assumed I was merely going through a purge phase that would pass, but it never did. This stuff has been nothing but a nuisance. All it did was dry out my skin. I'm sure it works great for some people, but it didn't do a thing for my acne and oily skin.