Scientists in Britain are warning that there is no evidence to suggest herbal medicines "tailored" to the individual do actually work; they also say such concoctions may even be harmful.
According to a study by a team from the Peninsula Medical School, a partnership between Exeter and Plymouth universities and the National Health Service in Devon and Cornwall, they found no convincing evidence that suggested herbal medicines "tailored" to the individual are effective.
The team arrived at this conclusion after a wide search for randomised clinical trials of tailored treatments across the world, in any language; they looked at 1,300 published articles on the subject and analysed the only three randomised clinical trials in existence.
They also contacted 15 professional bodies but were still only able to find the three trials.
The team are also dubious as to the skills of practitioners in Britain who offer treatments specially formulated for individuals.
The study comes at an opportune moment as authorities in Britain are currently reviewing the law in relation to the regulation of this field, and one of the factors it hopes to clarify is how many such practitioners there are at present in the country.
Practitioners generally offer a wide variety of treatments for conditions ranging from minor skin ailments to cancer, using a multitude of herbs, drawn from different cultures.
Chinese, Ayurvedic and Western herbal medicine, have all become increasingly popular over the past 20 years where practitioners mix different combinations of plant extracts to treat ailments such as asthma and arthritis.
The team say while there were many herbs which have health benefits, studies on these tend to involve standard preparations or single herb extracts.
One study compared a tailored Chinese herbal preparation with a standard herbal preparation and a placebo for irritable bowel syndrome (IBS).
The other two compared tailored treatments with placebos for chemotherapy-related toxicity in cancer patients and osteoarthritis and found no statistical differences between tailored preparations and placebos in either the osteoarthritis or cancer study.
Tailored treatment did seem to work better than the placebo in IBS, but it was not as effective as the standard treatment.
Dr. Peter Carter says while these trials did not suggest that patients had suffered ill health as a result, there were serious risks attached to the tailored treatment which included herbs interacting negatively with each other, as well as with prescription drugs.
The researchers say herbs may be contaminated or even toxic, and their strength misunderstood by the practitioner and there are many issues regarding expertise such as a practitioner being able to make a proper judgement and knowing when a client is displaying symptoms that really should be assessed by a doctor.
The National Institute of Medical Herbalists says it is impossible to draw conclusions from three small studies with "questionable methodology", and herbalists often found themselves unable to obtain the funding necessary to carry out rigorous trials.
They say people often resort to herbalists having tried the orthodox approach with no success.
They agree that there are issues regarding the expertise of practitioners and look forward to government regulation which may impose a high standard of training on anyone who wants to register as a practitioner.
Doctors in some countries practise phytotherapy, which uses extracts from a single plant and closely follows the principles of pharmacology; this is often confused with traditional herbal medicine.
The £191million industry in over-the-counter remedies in fact has little scientific basis.
In the UK alone there are as many as 1,000 registered individualised herbal medicine practitioners and an estimated 3,000 traditional Chinese medicine practitioners; it is not necessary to register in order to set up a practice.
Experts say the general public is not capable of differentiating between different types of herbal medicine and many want them banned completely.
The study is published in the Postgraduate Medical Journal.