B5, also known as Pantothenic Acid, is indeed a vitamin and by using it in large amounts it can reduce your acne. I'm using it almost a year now and I'm on a dosage of 3g/day which results in 99% clear skin (for me). Some people need more (10g/day) to see any results, others like me are fine with a relatively low dose. Do a search on the forum for B5 and I'm sure you'll find more helpful information. Also searching on the net for the original Dr Leung B5 study should give you more info.