Temporary henna tattoos are a fun way to decorate your skin without making a permanent commitment. Derived from the plant Lawsonia inermis, henna is commonly used as a natural reddish-brown dye. In India, the traditional application of henna to the skin is known as Mehndi. The longer the paste is left on the skin, the darker the resulting design. Though a number of factors affect how long a henna stain lasts, it generally wears off after a couple weeks. Though there is no foolproof way to remove a henna tattoo, if you need to get it off your skin faster, try soap and water combined with vigorous exfoliation.