The marketing of detox products is to be investigated by the government after the BBC drew its attention to some of their medical claims.
Detox is one of many lifestyle fads
The Medical Health Care Products Regulatory Agency (MHRA) is taking action based on investigations by Real Story's Doctors on a Detox programme.
Some detox products claim to enhance the immune system, relieve pain, flush out toxins and stimulate circulation.
But the programme said they had not undergone proper medical tests.
Medical claims can only be made after rigorous testing.
It is a criminal offence under the Medicines (Advertising) Regulation Act 1994 to issue an advertisement relating to a relevant medicinal product without a licence.
A spokesman for the MHRA said: "Licenses will only be granted after the safety and efficacy of products have been shown in clinical trials.
"Any product making a medical claim has to prove that quality standard. The consumer has to be able to trust what they buy."
The MHRA is now writing to a number of detox product manufacturers to ask them to withdraw any unproven medical claims.
Nutritionist and TV presenter Gillian McKeith's 24 hour Detox claims to "cleanse and normalise your body's vital organs, including liver, bowels, gall bladder, spleen and abdominal intestine system".
According to the MHRA this is a medical claim which requires the product to be tested and licensed.
McKeith's company told the BBC they believed the claims complied with current legislation and that "packaging is changed immediately if it is found to be out of line."
SlimLife Detox Foot Patches claim to flush out harmful toxins and boost the immune system.
SlimLife told the BBC they would be discussing the claims made for the product with the MHRA but an independent trial of 84 people had tried the product and the response was excellent.
Shapechangers Detox Wrap Deluxe Home Kit claimed their clay wraps could soothe psoriasis and eczema.
Manufacturer Sirius Blue said the medical claims were no longer made, although they acknowledged that old stock was still being sold.
Doctors on a Detox, a Real Story programme, is broadcast on Monday on BBC One at 1930 BST.
Do you follow a detox plan? Or do you think they are a waste of money? Should detox products undergo medical tests?
There is not a scrap of evidence that many of these products do what they claim to do. The MHRA provides people with assurance that a medicinal product does what it says it does and ensures information is given on side effects. This is certainly not the case for so called natural health remedies. Surely it would be far better for people to eat in a healthy way and exercise in the first place rather than rely on fad remedies to "energise" or "cleanse" them.
Gareth Girling, chelmsford
I find lots of manufactures tell lies about their products. The supermarket is full with products that calm health benefits without any real proof. They sometimes claim there products are high quality by poorly trained staff but then you find you can much better quality else where.
Emmet Mc Donagh, Athy
This is yet another cynical attack on natural health. We know that biochemistry is at least 20 years ahead of medicine and can explain the reasons for supplementing, detoxing etc. Natural products have a safer record than food itself, yet bodies such as the MHRA act as if they are protecting us whilst behind the double-speak they are in fact protecting the pharmaceutical industry which thrives on ill-health, and which is responsible, ironically, for thousands of deaths annually. Natural products are not medicines. The latter work by their toxicity, the former are what the body requires for life.
Jim Cooke, Newburgh