I've lost about 6lbs in 2 weeks after taking Alli, and that's been with a slightly lower fat diet than I'm used to. I hit a plateau for about 2 months, and nothing would shift the weight, then I started on Alli and the 30 day shred, and like I said - 6lbs in 2 weeks Alli and 1 week 30 day shred.
Lostgirl: it's recommended to combine it with a low fat diet to minimise the side effects. Iirc - Alli ensures that about 50% of the fat you eat passes through you and doesn't get absorbed. So, it won't work with a no-fat diet, and the lower fat your diet (assuming you replace fat calories with carb or sugar calories) the less effect it will have.
I've found it very good if I want to eat high protein food that usually has a high(ish) fat content too - fish, eggs and nuts. As long as I keep my portions fairly small, I find the protein fills me up for a long time, and with the Alli, only half of the fat is absorbed. For example, I used to have toast and honey for breakfast. Now I have toast with peanut butter - I know that half the fat from the peanut butter will be absorbed, but the protein in it will keep me going for longer than the honey would have done.
I think much of it's effectiveness is about how you use it, and whther you use it as a stick to beat yourself up with, or as something to give you a helping hand.
I should get commission for this stuff