It's not just a sign that you came back from a family cruise anymore—henna dyes are making the jump from the floral patterns on your skin to the brow area, and can be a natural alternative for those who shy away from traditional brow tinting formulas. "The main difference between the brow tints we use in our spa and henna brow tints is that the henna formula is natural and doesn't require a developer. It processes with the proteins in your hair, whereas the vegetable dyes we use require hydrogen peroxide to develop the color," explains Michelle Schlekewey, director of spa and fitness at Golden Door Spas. "When used in your hair, henna is considered permanent, but it fades away naturally within 2 to 4 weeks on your brows, similar to the time frame of a vegetable-based tint." You'll have to be selective with your color choices, however, since henna is available in far fewer shades, usually spanning the spectrum from red to brown.
The only downfall? The process can take forever. "Henna can take around 2 to 4 hours to process, so you put it on, put your brow under plastic, and wear that for a few hours, whereas the regular vegetable dye takes about 10 minutes," Schlekewey tells us. "Some people can get a reddish tint the first time around, so you end up having to reapply the product in order to get more depth, so it can be a long night tinting your brows." That being said, the formulation is usually found in an at-home kit, though Schlekewey notes that many natural salons and spas may carry the service—just research your options, and seek out some before and after pictures for reference, as you would with any salon treatment. "The nice thing is, people who are sensitive to the hydrogen peroxide in other brow tints won't have a reaction to the henna since it is completely natural," she adds.