ABC has a good article about Zetacap. Zetacap is being promoted as a 'gastric bypass pill'; as a far cheaper way to 'shrink' your stomach.
The company selling Zetacap says it contains a secret ingredient that will form a filling gel in your stomach and make you feel very full. But Zetacap has not been tested by the FDA because it has only natural ingredients.
The article suggests it would be better to just eat high-fiber foods to get the same feeling of fullness and alleviate hunger when you are on a diet.
See a list of ten high-fiber foods here.