Henna and colours for stunning hair: When do they become harmful?

Mailanchi, or henna, a plant-based powder made from the dried leaves of the henna plant, have long been used as a plant-based dye to make designs on our hands during special occasions and as a hair colour. The natural henna powder, which leaves an orange to brown stain, is traditionally considered excellent for hair as it strengthens the hair shaft, along with adding colour. It is also said to be good for scalp health and provide UV protection. However, these days, many people complain that the regular use of henna makes the hair dry and weak. Why does this happen? Dr Sapna Surendran, Senior Consultant Dermatologist at the Caritas Hospital and Skin Avenue Clinic, Kottayam, explains.

When henna damages hair
According to Dr Sapna, henna powders bought from shops often have agents that affect hair health. "They often have PPD (para-phenylenediamine) and other colouring chemicals, same as in permanent hair dyes," the doctor says. PPD is a synthetic coal-tar dye used for industrial purposes. The chemical's use in limited amounts is legal. "However, when it's used repeatedly, the chemical can make hair dry and result in shaft breakage. It's also something that triggers allergies like irritation and sensitivity, widely," she explains. 

Impact of regular hair colour use
There are many types of hair colours, says Dr Sapna. "Some of them act as a coating over our hair and get removed after a few washes. However, many permanent hair colours enter the outer layer, or the cuticle of the hair. When we repeatedly use such hair colours or dyes, the cuticle gets weak and hair breaks fast," explains the doctor. Hair dyes can also have the same impact, she says. First of all, the dye should only be applied to one's hair, not the skin, she says. It's important to carefully check whether the hair colours and dyes one purchases suit their hair, explains the doctor. "If it causes skin sensitivity, it shouldn't be used any further. Even then, once the sensitivity heals, the portion of the skin can have a change in colour. Moreover, make sure to apply the dye only to one's hair, and not on the skin.