Last month was busy for herbal medicine. In one week, there was the launch of Kava, the root of a Hawaiian plant that seems to be an effective tranquilliser; the publication of a pilot study suggesting Maitake mushroom pills can reduce itching and soreness of thrush by 40 per cent; and a high-level conference on the possible dangers of herbal medicine. Which received the most coverage? The dangers.

Herbal medicines are perceived as safer and more 'natural', and we now spend £150 million a year on them. This has prompted drug companies and the medical establishment to demand proof of their effectiveness and safety. Where they have been tested to the standard required by pharmaceutical drugs - double-blind placebo-controlled trials - some herbal remedies have revealed impressive results.

At a conference organised by the Novartis Foundation, the charitable arm of the pharmaceutical giant, Professor D Loew of the University of Frankfurt ran through the attributes of four herbal remedies almost everyone has heard of: hawthorn for heart problems; ginkgo biloba for memory failure due to Alzheimer's; St John's wort for mild depression; and saw palmetto for shrinking a benign swelling of the prostate. All have been through proper trials and performed as well or better than standard drug treatments, with fewer side effects.

You might think trials would be under way to test the properties of other herbs, especially those that appear to mitigate chronic conditions conventional medicine is so bad at treating. There is no shortage of candidates. To take a few studies recently reported in respectable medical journals: an ingredient in milk thistle - silymarin - has been found to give 'highly significant protection against tumour promotion' in animals; a mixture of Chinese herbs 'significantly improved survival times' of cancer patients also being treated with chemotherapy; stinging nettle was found to 'reduce the pain and stiffness or arthritis' as effectively as aspirin-type drugs and an extract of elderberries was reported to 'remove 90 per cent of the symptoms of 'flu after two days' compared with six days for the placebo.

There are hundreds of studies suggesting that herbal treatments can be effective. Few constitute proof at the level demanded of new drugs.

Some were not double-blinded, others were not compared with a placebo and almost all were small - 10-50 patients, as opposed to the hundreds in official drug trials. Nearly all end with a recommendation for further research. But proper studies are rarely done into herbal remedies and the reason is simple - money.

Professor Edzard Ernst is head of the complementary medicine department at Exeter University, yet he confesses he was unable to get even £200,000 to run a trial on one promising herb. His penury is in marked contrast with the £2 billion spent every year in the UK on conventional medical research. An estimate puts the total amount spent on complementary medicine research over the last 15 years at a mere £3 million.

The reasons for this are patents. You can't patent stinging nettles or milk thistle, so drug companies can't earn big money from them. But lack of research allows drug companies and the medical establishment to concentrate on the issue of the safety of herbal remedies.

There are issues of safety with herbs - certain Chinese herbs have been linked with liver damage, for example. But what is less reported is that the size of the problem, compared to that created by pharmaceutical drugs, is tiny.

Of the 1.8 billion adverse drug reactions listed in a WHO database, only 9,000 concern herbal remedies.

'Herbs have been used for a long time,' says Professor Peter Houghton, lecturer in pharma-cognosy at King's College, London. 'So there has been a long process of weeding out the dangerous ones.'

The point about efficacy and safety also cropped up at the launch of a new product using the Hawaiian herb, Kava. This has been subjected to at least three proper trials in Germany which show it to be an effective treatment for anxiety. 'It is just as effective as conventional tranquillisers,' says Peter Conway, director of the London Clinic of Phytotherapy, 'but without the side-effects.'

'Herbs are complex substances compared to drugs, which are chemically very simple. That's why we can build up a tolerance and become addicted to drugs but not to herbs,' he adds.

What prospective patients need is properly funded research, rather than the current concentration on the relatively minor dangers.