I've seen arguments both ways. There is an Alli thread in the General Diet Plans forum if you want to have a look.
http://www.3fatchicks.com/forum/show...highlight=alli
I agree with irisheyes. Supplements like this are intended to assist you in losing weight, not do it for you. Please don't get me wrong. I'm not saying you're looking for an easy way or anything, but just be careful not to be dependant on a pill. I did that years ago and gained all the weight I had lost plus some after I quit buying my magic pills.