This product is essentially a concentrated version of salicylic acid. Although it's marketed here as a corrector for complexion issues salicylic acid is used in a variety of products for all kinds of skin problems including for reducing corns on the toes. I'm using it for several matters: to lighten very dark patches on both my pinky toes left by tight shoes, a spot of hypo-pigmentation on my right shin from a minor scrap when wearing shorts, and for the occasional dark spot on the face from periodic bouts of adult acne. I find that this serum works well on all of these issues. Because its more concentrated than similar products I've come across it does work faster, though I can't attest that it works quite as fast as the promo statements seem to imply. Still, it's a better choice than any alternative I know about. The 1.7 ounce bottle will last for several months and the design of the dropper makes it easy to target what's a pretty watery liquid to the right place in the right amount. It's a useful item for general skin care.