Straight-up Benzoyl Peroxide in 5%.
Great product, works well at disinfecting the acne area. I don't have very bad acne, but it works well as a spot treatment. I've given this to friends who have cleared up their acne very significantly in a few weeks time. I'm surprised doesn't dry up my skin, despite it being at the strength it is (and I have dry skin and moisturize minimally), thus gaining more favor! As for advice for those with severe acne, if you check out Goss Makeup Artist's video on clearing acne, you can follow the regime he does (he uses benzoyl peroxide, though at 2.5%) to clear up major acne. He used a moisturizer and sunscreen, go watch it it's excellent!
I love it!
Ive been using this product for about a year or 2 and i like it alot. i have horrible acne and pores that are probably about 10 feet deep, and this product cleared up most of my skin in a few weeks. the only problem i have with this product is that it really dried out my skin, which happens to be very oilly to begin with, but i work around it, because of its results