The people giving this bad reviews aren't doing it right. I know this because I took this drug for 6 months and lost 60lb (I lost 20 before starting alli for a total of 80lb). Did I lose all that weight just because of alli? No, but it was an aid, a helper, an ALLY, if you will.
This product tries to teach you to eat differently, and you really REALLY have to if weight loss is something you want to keep up until you're at a normal weight. If you're constantly having stomach pain, gas, and leakage, then you're eating too much fat. Plain and simple. Most people don't understand what's in the food they're eating, or what it's role in your body is. I know people that eat a deli sandwich and think that most of the calories come from the 6 slices of turkey inside, when in reality, that only contributes around 60 calories, and the two huge pieces of bread holding the sandwich together have 200+ combined. Food that's cooked with oil in the pan, vegetables topped with butter, any nut or seed, anything crispy or breaded, all of that has fat, and you need to be aware of how much you're taking in.
While I was taking alli, I ate an extremely low fat diet. I'm talking almost no fat here. I never once had a problem with the drug, and I did lose lots of weight. I'm now in excellent physical shape, and run/train everyday. My eating habbits never reverted back to their old ways because "I" changed the way I ate. I didn't just "go on a diet" I really started seeing and treating food differently. I don't eat hyper low fat anymore, because that's not the healthiest thing for what I do. (Just as a note, I love food, and I love the food I eat everyday. It just happens to be healthy. You may have to sacrifice things you're used to eating, but that doesn't mean you're giving up taste and satisfaction)
There's no one golden rule for weight loss, there's not easy solution, there's no absolutes. This drug does EXACTLY what it says it does, and if you have side effects, then you're not upholding your end of the deal. The drug can only do what it's supposed to do...the rest is up to you. It does what it does perfectly, and if you let it help you, it will.