An advert for a patch which, it is claimed, could help dieters lose a stone in a fortnight has been banned for “promoting bad medical practice”.

The Advertising Standards Authority (ASA) said the internet advert for the Pink Patch, which appeared on social networking site Facebook, was "irresponsible".

The advert said: "Want to lose the tummy?" This was replaced by further text reading "Drop a stone in 2 weeks!"

CYC Marketing, the company behind the Pink Patch, claimed the device works by releasing herbal ingredients into the body that promote weight loss.

ASA said it had not seen any evidence that the ingredients, when combined in the patch, resulted in any weight loss. It said in a statement: "The evidence did not persuade us that wearing the Pink Patch would result in a loss of body fat," and promoting weight loss at a rate of one stone in two weeks was "contrary to good medical and nutritional practice".

ASA also found that some of the studies for the patch were carried out on animals, not humans. This is contrary to the ASA code, which states all claims for weight loss should be “backed by rigorous trials on people".

No one from CYC Marketing was available for comment.