Henna is a dye prepared from the plant Lawsonia inermis, also known as the henna tree, the mignonette tree, and the Egyptian privet.
Henna has been used since antiquity in ancient Egypt and the Indian subcontinent to dye skin, hair and fingernails, as well as fabrics including silk, wool, and leather. Historically, henna was used in West Asia Including the Arabian Peninsula and in Carthage, other parts of North Africa, West Africa, Central Africa, the Horn of Africa and the Indian subcontinent.
Whole, unbroken henna leaves will not stain the skin. Henna will not stain skin until the lawsone molecules are made available (released) from the henna leaves. However, dried henna leaves will stain the skin if they are mashed into a paste. The lawsone will gradually migrate from the henna paste into the outer layer of the skin and bind to the proteins in it, creating a stain. Natural henna pastes containing only henna powder, a liquid (water, lemon juice, etc.) and an essential oil (lavender, eucalyptus, tea tree etc.) are not "shelf stable," meaning they expire quickly, and cannot be left out on a shelf for over one week without losing their ability to stain the skin. After henna stains reach their peak color, they hold for a few days, then gradually wear off by way of exfoliation, typically within one to three weeks.
Henna body art was regarded as having Barakah (blessing), and was applied for luck as well as joy and beauty. It has been popular in more and more countries and now celebrated worldwide.