This hot beauty trend can last up to 6 weeks. Henna stains the skin from 2-14 days and stains the brow hair for up to 6 weeks, depending on your skin type and lifestyle. The henna sets to a powder like matte finish that fills in the brow and adds definition where hairs are sparse or non-existent. Henna also has other benefits that can help to strengthen, restore and improve the natural condition of the eyebrow hair and growth.