I left it on for 45 minutes, my hair is naturally dark dark brown. Every other bleach I have used only got my natural color up to orangey gold after the first bleaching even when I used 30 vol. I haven't ever used 40 vol. I was going to use 30 vol this time, but the box only calls for 20 vol. So I was like ok, we will see what it does.
I was pretty amazed when I checked my roots at the 45 minute mark and they were a light yellow color. I don't think I'm going to use anything else lol. My scalp was only mildly tingly and not burny at all.
^ even more reasons to try it......^ *wanna go do my hair now*
@_@