Henna (Lawsonia inermis) has been traditionally used for hair care for centuries, particularly in South Asian, Middle Eastern, and North African cultures. Its primary uses include coloring the hair, conditioning, and purportedly strengthening the hair shaft. The leaves are dried, powdered, and mixed with water to create a paste that is applied to the scalp and hair. Folk traditions claim that henna can promote hair growth, reduce dandruff, and improve scalp health, largely attributed to its antimicrobial and astringent properties.

From a scientific perspective, there is limited evidence supporting henna's efficacy in directly improving hair strength or promoting growth. Some studies have demonstrated its mild antimicrobial and antifungal properties, which could potentially benefit scalp health and indirectly support hair condition. The lawsone dye in henna binds to keratin, coating the hair shaft, which may increase the perception of thickness and shine. However, rigorous clinical trials substantiating claims of enhanced hair growth or significant therapeutic benefits are lacking. The evidence supporting henna's use for hair is thus primarily traditional, with a modest scientific basis for its role as a natural hair dye and mild scalp conditioner.