Well, i've just finished my first period whilst being on Xenical. I've noticed that this month I've been lighter than usual and haven't had a break out either!
This for me too. When I gained it went back to how it used to be. For me I felt it was the weight loss, and maybe it's impact or hormones, (and maybe drinking loads of water) that lead to the changes. Whatever the cause, it's a nice side effect!