I used an earlier version of this a long time ago because -- why not.
It turned me black. Seriously. (Not the race, the color.)
I am brown already and went from medium/dark brown to midnight black, like I was from Somalia or something. It gradually faded over a month or so.
It does work, especially for females.
Not sure if this version has the same effect, but I did in the Army and my unit started singing "Buffalo Soldier . . ." behind my back.