Henna is a dye that is typically derived from the dried leaves of the henna shrub, Lawsonia inermis. The leaves of the henna plant contain a natural coloring pigment called lawsone, which is an orange-reddish dye that binds with keratin in our skin to stain it. Henna has been used since antiquity in ancient Egypt, the ancient Near East, and the Indian subcontinent to dye skin, hair, and fingernails, as well as fabrics including silk, wool, and leather.

To make henna paste, dried leaves are ground into a fine powder and mixed with oil or water. Many artists use sugar or molasses in the paste to improve consistency and keep it stuck to the skin better. The dry powder is then mixed with liquids, including water, lemon juice, strong tea, and other ingredients, depending on the tradition. Other ingredients can be added to henna to darken the color and lengthen the time that the tattoo is visible. This is referred to as “black henna.” One of the additives frequently used to make a darker color is para-phenylenediamine, an ingredient in hair dye. However, para-phenylenediamine or PPD is not approved for direct use on the skin.

In summary, henna is made out of the dried leaves of the henna shrub, Lawsonia inermis, which are ground into a fine powder and mixed with oil or water to make a paste. The paste is then applied to the skin for temporary tattoos.