Eyebrow tinting—you've probably heard about it or maybe even tried it, and today, I'm gonna give you the low-down about what it actually is, how much it costs, how long it lasts, and, believe it or not, why it's illegal in a lot of the country. Yup, seriously! And if you didn't know this, it's even more important for you to keep reading about all the need-to-knows before booking your appointment. An , as a refresher, is (think: , even without the tinted ).

Unlike other permanent eyebrow treatments, like and , . The only downside? Brow tints aren’t regulated by the FDA (although, to be clear, many beauty treatments aren’t), which means it’s on , the consumer, to find the safest and least-risky salon or spa. So, to help you, we tapped brow experts (founder of in NYC), (founder of ), and (founder of in NYC) to talk all things eyebrow tinting, below.

Eyebrow tinting involves applying a . The benefit of tinting your brows vs. just filling them in every day with a brow gel or eyebrow pencil is that a tint can dye the tiniest and finest hairs around your eyebrows, helping to make them look thicker, fuller, and longer.

Just remember that eyebrow tinting —at least, not for long. “The tint will stain your skin at first, so your eyebrows might look fuller initially, but the stain will fade after a few days,” says brow expert Umbreen Sheikh. So if you’re looking for thicker-looking brows on a daily basis, you’ll need to “combine your eyebrow tint with other products, .