We are concerned about the safety implications of an unregulated herbal sector

Lords committee

But the committee slammed some popular treatments including crystal therapy and iridology - saying there was "sparse evidence" to prove they worked.

One in five Britons now seeks complementary and alternative medicine (CAM) treatment such as aromatherapy, acupuncture and homeopathy and as a nation we spend �350m a year on "natural remedies".

However, many of the 40,000 therapists who practice in the UK have weak, or non-existent regulation compared with doctors, dentists and nurses.

Unsupervised

Virtually anyone can set themselves up as a practitioner, regardless of their training, and then practice unsupervised.

Although there is growing evidence that some alternative remedies appear to be effective in treating some conditions, the body of properly-organised scientific study literature is relatively tiny compared to conventional medicine.

Only two complementary therapies - osteopathy and chiropractics - are currently regulated by acts of Parliament.

Britons spend �350m a year on alternative remedies

The Lords committee, headed by Lord Walton, has spent more than a year investigating alternative medicines in a bid to improve regulation and training and decide which therapies should be available on the NHS.

They concluded that only therapies which have statutory regulation or "a powerful mechanism of voluntary self-regulation" should be available on the health service, and then only through referral from a GP.

Both crystal therapy, which uses gems and crystals to help healing, and iridology, which claims to be able to discern underlying disease through subtle changes in the appearance of the eye, were condemned.

The report said that other therapies such as the Alexander Technique, aromatherapy, hypnotherapy and reflexology should be subjected to voluntary self-regulation and should "control their claims according to the evidence available to them".

Hepatitis infection

Earlier this year, the British Medical Association called for CAM to be regulated in order to protect the public.

A recent case, in which a registered doctor spread hepatitis infections by using unsterilised syringes at his alternative health clinic led to the doctor being struck off.

Most practitioners are fully competent in what they do, they provide a first class service and it is a very safe service

Michael Endacott

But this was only possible because the practitioner was also a registered doctor and could be disciplined by the General Medical Council.

The Lords committee called on the Department of Health to provide the public with independent information about alternative therapies.

The report said: "There is a clear need for more effective guidance for the public as to what does or does not work and what is or not is safe in CAM.

"There is no central information for provision and healthcare practitioners - thus the media and other unregulated sources have an undue influence on opinion in the field."

'Safe service'

The committee concluded: "We are concerned about the safety implications of an unregulated herbal sector and we urge that all legislative avenues be explored to ensure better control of this unregulated sector in the interests of public health."

However Michael Endacott from the Institute of Complementary Medicine told the BBC there was a high level of expertise among therapists.

"Most practitioners are fully competent in what they do, they provide a first class service and it is a very safe service," he said.

The government has said it will use legislation to improve the regulation of the various types of practitioner, giving bodies the power to oversee the professions, and ban bad therapists from working.

Phil Douty, managing director of Boots Wellbeing Services, which has begun to provide complementary therapies in some of the chemist's high-street branches, said: "Complementary therapy is an important and growing market.

"It's vital that the professionals within that market are recognised through regulation so that their customers can be entirely confident of the highest level of service."