It's powder MSM. Ok I'm 31 now and I have gotten progressively worse Acne over the years it's all over my chest and back. I also have scars to boot. The only way before that cleared it up was birth control pills and I don't like the way they make me feel and they made me gain weight. I had even done accutane 3 x's and it made me depressed and the Acne came back. I started taking the MSM power for joint pain and a side effect of regular use seemed to be that my Acne cleared up within a week! I started with the instructed amount and then increased it to about 3000 mg every other day and 1000mg every other day. This is amazing to me becasue it took 3 months of the bc pills to clear it. I am not trying to sell anything and I have no idea if it will work for anyone else but it sure does make my skin look soooo nice. I think it even gives a plumping effect (not fattening which would be negative but a nice supple look of youth and health). The brand I bought at the local health store is about $9.00 USD and it's called TriMedica and they have a web stie on the bottle but I haven't been to look at it yet. It's TriMedica.com so for what it's worth there is my little story. It says it's the only one that is proven but then they may be bias, lol.