Kojic acid is derived from a variety of fungi and organic substances and is present in skin-whitening creams used to diminish dark areas resulting from excessive pigmentation in the skin. You can buy raw kojic acid but this substance may cause damage to your skin unless it is diluted in a cream or gel. Kojic acid may help diminish or eliminate sun freckles, melasma or other pigmentation when used correctly, although skin conditions and their treatment should always be discussed with a health care professional before beginning a treatment program