My mom used it during some time, and we (the rest of the family) are all happy she doesn't use it anymore.
Together with the oily you-know-what came the most awful smell (according to the doctor, this was "normal").
Also, it gave my mom other problems. It only helps when you eat a lot of fat, not against the sugar you eat (so you still need to find a way to control your sugar-eating-habbits) After a while, my mom was on weightwatchers (i.e. not that many greasy stuff) and she still took the Xenical, and since she didn't eat "enough" fat things, she got stomac problems and so on.