. The skin whitening process is gradual, it does not happen overnight. It normally takes 8 to 12 weeks before you see the maximum results, however, this really depends on your skin sensitivity. This kojic soap can be used on both face and body. It can remove dark areas or skin blemishes such as: acne or pimple scars, melasma, whiteheads, blackheads, hyper pigmentation, dark elbows, knees, inner thighs, bikini area, butt, knuckles, underarms, old scars, etc