Alli, a half-strength version of the prescription-only Xenical, which interferes with the body's ability to digest fat, and Appesat, a seaweed extract, which is said to swell up and trick the brain into thinking the stomach is full, will cost £1-a-day and £29.95 for 50 capsules respectively.

The first and only over-the-counter product for weight loss approved by the Food and Drug Administration will be available Friday, June 15.

GlaxoSmithKline Consumer Healthcare [NYSE: GSK] announces that alliâ„¢, the only FDA-approved over-the-counter weight loss product will be on shelves of pharmacies, grocery stores and mass merchandisers nationwide later this week. alli is designed to be a partner for overweight adults willing to change how they eat and lose weight gradually. Adding alli to diet and exercise can help people lose 50 per cent more weight than with dieting alone.