Tranexamic acid is a synthetic derivative of the amino acid lysine, which is used in skincare to treat hyperpigmentation & post-inflammatory acne scarring. Studies have shown this to be as effective as the gold standard prescription ingredient hydroquinone, without any of the associated irritation, based on a panel with medium-toned skin (50 women of Iranian descent). It is believed to work by suppressing some of the mechanisms in the skin, which lead to the production of excess melanin.