O.k.
It's a glycolic acid, with a green-tea follow-up, meaning I dab it on for about a minute, wash off w/an arcanic?? cream, another one of those I have to look up (an herb) .
I do it, oh, maybe about once every 2 - 3 weeks or so.
BUT - in the winter, that's different. Vitamin D has a lot to do w/this I've noticed, as well (the dark circles) as well as heredity.
Again, not an expert and don't know why. Just follow my instincts and they seem to fix what ails me. They really do