Yes, natural henna is safe. It doesn’t hurt you or cause any pain at all. But please don’t apply black henna, for more information please read these dangers of henna.
Henna is applied using a bottle or a cone like a pastry cone. It is put on the skin, like a lotion in a pleasing pattern. It doesn’t hurt at all since only the henna is touching the skin, and it is cooling and soothing. The henna is left on the skin for several hours and then when the dry henna is removed the design is in the top layers of skin. As the skin naturally exfoliates, the design fades away.