Although alli is sold as an over-the-counter medication, it is only approved for use by overweight individuals who are over the age of 18. GlaxoSmithKline, the manufacturers of alli, call the pill a comprehensive program, and recommend that it be combined with a low-fat, low-calorie diet and a healthy exercise plan. When you purchase alli-usually for about $50 a month-you have the option of visiting the company's website. There, you can register as a user and receive a customized exercise and eating plan. A big part of the eating plan is keeping fat to less than 15 grams per meal. Although alli does block some fat, eating too much while on the program can result in side effects.