I know it has been said before but if you are going to lose weight you need to take in fewer calories than you burn during each day.
The traditional way of doing this is to follow a diet that restricts the number of calories you eat and at the same time increase your exercise so you burn more calories.
Alli belongs to a group of drugs that can help this process, but the important word there is "help". Taking Alli and making no other changes is unlikely to lead to significant weight loss and could lead to some very unpleasant side effects that have lead to criticism of the drug.
Alli is basically a "fat binder", that is a drug that stops fat from being absorbed. It is not actually a new drug but has been available on prescription for some while. The difference is it has now been approved to be sold over the counter which has reduced the price and made it more available.
It works by attaching to the enzymes which your body produces to help it absorb fat. This means about a quarter of the fat you eat and all the calories that fat contains passes straight through your body.
The advice is that if you start taking alli you must reduce the amount of calories and particularly fat that you eat. The people that did not follow this advice are the ones that had problems. Basically the more fat you eat, the more fat that will pass through you.
If you continue to eat a high fat diet you will have more fat to pass. This can lead to stomach cramps, soiling of underwear and uncontrollable gas with oily deposits. Follow the cut down advice and you should have relatively minor side-effects, if any.
Using alli sensibly could result in a 50% increase in weight loss, that is for every 2 pounds you lose alli could make you lose one more. That should certainly give a boost to diet efforts.
Of course if you are really serious about fat loss you should combine you diet changes with some moderate exercise. Don't go in to for heavy exercise straight away. Instead start from where you are and gradually increase. You should be aiming to make changes you can stick to not something you will burn out with after just a few days.
So, does all work for weight loss? The answer is it can certainly support you and add to your weight loss but you need to make sure you use it as it was intended to be used.