GlaxoSmithKline said Alli the weight loss product will be on shelves of pharmacies, grocery stores and mass merchandisers nationwide later this week. The drug, which was formerly the prescription drug Xenical, will be the only over-the-counter weight loss product approved by the U.S. Food and Drug Administration.

Adding alli to diet and exercise can help people lose 50 percent more weight than with dieting alone. alli is being supported by an unprecedented multicultural and bilingual educational effort, making it more than just a pill but a comprehensive weight loss program.

"Alli is not for people looking for miracle pills and overnight results. It offers consumers a proven, safe, over-the-counter option to help them lose weight gradually," said Steven Burton, GlaxoSmithKline Consumer Healthcare's vice president of weight control. "We recognize people need help to lose weight and that is why we are so excited that Alli is now available to provide adults with the support they need."

The alli starter pack comes in a variety of sizes – 60, 90 or 150 capsules and is priced at approximately 60 cents a capsule or $1.80 per day. The recommended dose is one 60mg orlistat (the active ingredient in alli) capsule, three times a day, with meals containing fat.

The drug acts by blocking about 25 percent of the fat in foods, reducing the amount of fat and calories absorbed by the body. If the drug is combined with high-fat foods, users are likely to suffer "treatment effects," such as having an urgent need to go to the bathroom.