TRADING watchdogs have warned of the risks of so-called slimming pills.
Officials in West Yorkshire say some of the cures will cut only pounds from the pocket and not from the waistline.
A survey by the county's trading standards found that few, if any, of the expensive quick-fix pills will actually cause weight loss.
Graham Hebblethwaite, divisional manager of West Yorkshire Trading Standards, said: " It is a constant problem.
"We continually get complaints from people about these so-called miracle pills, particularly those advertised on the internet."
He added: "These operators prey on the fact that it can be very difficult to lose weight.
"Our message to people would be that by eating sensibly and by doing some exercise, you should lose weight. There is no magic cure."
Some slimming products include improbable claims, such as:
* Slim while you sleep
* Mercilessly attacks, burns and eliminates fat deposits lMelts fat in your body by the gallon.
Prof John Garrow, an expert on nutritional treatments for human obesity, who works alongside trading standards officers, said: "Claims that a pill will dissolve away your fat are always untrue.
"Claims that the pill will speed up your metabolism, or reduce the calories you absorb from your diet, are usually untrue."
Trading standards will follow up any complaints about false advertising on miracle slimming products.
Prosecutions can be difficult, particularly on products bought and sold over the internet, but there have been some successes.
North Yorkshire Council successfully prosecuted a distributor who had been buying multi-vitamin tablets from a High Street shop for 2p per tablet, then re-packaged them and sold them as a diet pill for £2 each. He was jailed for 12 months.
Trading standards are working with the Food Standards Agency in order to tighten the regulations on `miracle' products.