What percentage of benzoyl peroxide should I look for in a spot treatment?
Concentrations of benzoyl peroxide products for acne range from 2.5 percent to 10 percent. This includes both over-the-counter and prescription options. Studies show that there is very little difference in effectiveness among the percentages, but the higher concentrations are more irritating. I recommend patients start out with a 5-percent concentration, and if it is well tolerated they can try increasing to 10 percent. If it is too irritating, I suggest decreasing to 2.5 percent. In general the back and chest are less sensitive than the face, so you can often use a stronger formula for those areas.