Review (5/5): Not bad!
My brows are already pretty dark but I dye my hair jet black (my natural hair color is a dark ash brown) so I wanted to try this to make things easier on the days I don't feel like filling them in. Minimal staining, I was pleasantly surprised, but it took 2 applications to get them noticeably darker. The first time I left the dye on for about 2 minutes, the second time about 4. If you're a natural blonde or redhead this would be a great kit for you, but I'd recommend trying the medium brown rather than this shade. Good stuff.