Henna comes from the plant Lawsonia inermis, a native shrub of India and areas of the Middle East. The dried and powdered leaves of the plant make the product commonly known as henna or mendhi. The powdered leaves have a long history of use as a dye for hair, skin, nails and other materials. Henna for hair comes in a variety of color options, including neutral, red and dark brown, and can be used to treat conditions such as dandruff.
History
Documentation shows the use of henna as far back as 5,000 years, according to Plant Cultures. Egyptians, Indians and Arabians used the dye, although its place of origin is a matter of debate. The plant and its uses spread through migration and trade, eventually reaching the rest of Asia, Europe and the Americas. Its primary uses included medicinal skin applications, body art, hair dye and hair treatment.
Properties
Dried henna leaves contain several properties useful in treating hair and skin conditions, such as dandruff. The plant has active constituents, such as tannic acid, gallic acid, mucilage and lawsone, the property responsible for the dyeing effect, as reported by Purdue University NewCROP program. Henna includes astringent, antibacterial, antifungal properties and screens ultraviolet light.
Dandruff
White flakes in the hair and an itchy or irritated scalp can signal a dandruff problem. The Mayo Clinic reports several possible causes of dandruff, including dry or oily skin, dirty scalp, dermatitis, eczema, psoriasis and fungus growth. Henna binds to the keratin in the hair, creating a protective layer and relieving scalp irritation. It acts as a conditioner while reducing oiliness, which may help reduce dandruff. Its antibacterial and antifungal properties can also treat dandruff, depending on the cause.
Using Henna
Henna for hair dyeing requires mixing the dried powder with filtered water. Adding other ingredients--such as lemon juice, tea tree essential oil and apple cider vinegar--can improve the treatment for dandruff. Different options for henna color make it versatile for almost anyone to use. Some shampoos and conditioners for dandruff contain henna and other ingredients to treat the condition, but do not result in a color change.
Warnings
While henna has FDA approval for use on hair, it can cause contact dermatitis. A patch test before use is recommended. Adulterants, including harmful chemicals, show up in some henna dyes. To avoid these chemicals, purchase henna from a reputable seller that guarantees the purity of the product. Some plant additives--including indigo, chamomile, cassia, alkanet and calendula--alter the color of the henna naturally,
References
- Plant Cultures: Henna History
- Purdue University NewCROP: Henna
- Mayo Clinic: Dandruff
- "The Green Beauty Guide"; Julie Gabriel; 2008
