Orlistat (120mg) is a generic prescription treatment that prevents 1/3 of dietary fat from being digested. It is cheaper than Xenical, but more expensive than Alli.
Xenical (120mg) is a branded prescription treatment that prevents 1/3 of dietary fat from being digested. It is the best-known weight loss tablet, but also the most expensive.
Orlos (60mg) is an over-the-counter treatment that prevents 1/4 of dietary fat from being digested. It is not as strong as Xenical or orlistat but is the only one available over the counter