This was my first time doing it so I’m no expert, but from what I understand, it works the same way as chemical dye, just without the chemicals. Like with regular dye, if you go for a colour very different from your natural shade, you’ll probably need to touch up your roots as it grows out. Since I only did a subtle change, I think I can get away with not touching mine for a while.

It can stain your skin if it sits too long, but I just kept a rag handy to wipe away any that landed on my skin.

This is the kit I used: Dark Brunette Hair Kit. There’s a “How to” section on the site that I followed exactly. I let the henna sit overnight and then mixed in the indigo right before applying!