We spend £1.6bn on them a year. But are they doing us any good?

Complementary medicines lead to healthy profits, but many do little for the patient

Complementary medicines taken to treat ailments from colds to cancer are thriving, and it is the better-off middle classes who are hooked, a report has revealed.

Complementary medicines taken to treat ailments from colds to cancer are thriving, and it is the better-off middle classes who are hooked, a report has revealed.

Herbal preparations such as echinacea, used to ward off flu, and St John's wort, taken for depression, are walking off the shelves and into the shopping bags of professional men and women.

Sales have risen 44 per cent in the last five years to £147m. They represent the fastest-growing sector of the over-the-counter pharmaceuticals market which includes painkillers, cough mixtures and flu remedies, according to the market analysts Mintel.

Growing disaffection with conventional medicine, fear of side effects of pharmaceutical drugs and increasing interest in "natural" alternative remedies are behind the boom.

Herbal and homoeopathic medicines have gained widespread acceptance, with increased distribution through mainstream retailers such as Boots fuelling the growth.

But there were warnings yesterday that many of the remedies are untested and their effects unproven in clinical trials. While most will harm nothing more than the consumer's pocket, some can cause serious adverse reactions, similar to those produced by medical drugs.

Among herbal medicines, echinacea and St John's wort have enjoyed the highest profile, which has stimulated interest in other herbs. Sales of homoeopathic medicines have grown strongly, led by Bach Flower Remedies. Aromatherapy oils used in massage and in cosmetic preparations such as bath oils are also selling well.

In a survey of 1,000 adults, one in five said they had used complementary medicine and two in five said they took vitamins or dietary supplements every day. Professional women dominate both groups, according to Mintel.

But while complementary medicines are bought mostly by 25- to 34-year-olds, this group is not particularly inclined to visit complementary practitioners. That is more common among the older 45-54 age group.

Vitamins are taken mainly by women in the 55-64 age group who want to ward off the signs of ageing and maintain a sense of wellbeing.

The survey found widespread support for the greater availability of complementary medicines, with one-third saying they should be available on the NHS. The total annual spending on complementary therapies and medicines is put at £1.6bn.

Edzard Ernst, Britain's only professor of complementary medicine, defends some herbal remedies but is sceptical of claims made for others. Among those with proven effects are hawthorn, which lessens the symptoms of heart failure, garlic, which lowers cholesterol, gingko biloba, which slows the decline of mental function in Alzheimer's disease, and St John's wort, which alleviates mild to moderate depression.

But Professor Ernst warned: "Some herbs are toxic and can damage organs such as the liver or kidney. Some preparations, particularly those from Asia, are contaminated with poisonous substances such as heavy metals.

"Occasionally herbal mixtures have been adulterated with drugs like cortocosteroids or other powerful prescription medicines. In all these events consumers can suffer serious harm."

Professor Ernst, of the Peninsula Medical School at the Universities of Exeter and Plymouth, says that owing to the lack of control over herbal remedies, they may vary from batch to batch depending on the soil, time of harvest, handling of the crop, method of extraction and storage conditions. "My advice is to buy from a reputable source."

There are serious dangers in the misuse of herbal remedies. A study of 32 of the most popular websites giving advice on complementary therapies for cancer found they were receiving tens of thousands of hits a day yet none of the 118 different cures they recommended had a demonstrated effect against cancer. One bogus treatment involved shark cartilage and laetrile, derived from apricot stones.

"It was quite an eye-opener and pretty scary stuff," Professor Ernst said.

Other nostrums over which there is doubt include the best-selling Rescue Remedy, brand leader among the Bach Flower Remedies, which is promoted as a cure for stress to be taken as a relaxant at the end of the day. Professor Ernst said: "The best available evidence to date shows that this treatment does not reduce anxiety. In the most rigorous clinical trials it proved to be no different from placebo."

Between 1968 and 1997 the World Health Organisation monitoring centre collected 8,985 reports of adverse incidents associated with herbal medicines, from 55 countries. However, this was a tiny fraction of the number concerning conventional medicines.

Complementarymedicines are subject to the Medicines Act and EU directives and require marketing authorisation if they make claims about their medicinal benefits. However, unlicensed herbal products can be sold if they do not make such claims and have been manufactured according to specific processes. An increasing number of products are now seeking this exemption by using careful wording in their product claims.

From 2006, herbal medicines will be regulated under an EU directive requiring them to demonstrate traditional use stretching back 30 years. Professor Ernst said: "This will maximise safety for the consumer so I welcome it on those grounds. But as a researcher I am doubtful. It will freeze our knowledge at the point when it is introduced."

St John's wort

What is it? Hypericum perforatum - a yellow flowering hedgerow plant that has been used for centuries as a herbal cure. Comes in tablet form or as herbal tea.

How much is it? £15 for 200 300g capsules; 23p a day.

What does it do? Hugely popular as a natural remedy for mild to moderate depression which can be taken without prescription.

Does it work? Good evidence from studies that it is effective against mild and moderate depression.

Echinacea

What is it? Echinacea purpurea is a big purple cone flower that looks like a giant daisy. Native to the prairies of America.

How much is it? Around £9 for 100 400g capsules; 37p a day

What does it do? The extract of the plant's root is said to be effective against colds and flu. Comes as a tablet or herbal tea.

Does it work?

Three different plant species make it difficult to assess. No clear evidence that it has an effect.

Vitamin C

What is it? Ascorbic acid, vital to the growth and maintenance of healthy gums and teeth. Found in fruit and vegetables, it boosts the immune system and wards off degenerative diseases. Available in tablet form.

How much is it? £7 for 100 500g capsules; 7p a day.

What does it do? Said to help to cure or prevent colds.

Does it work? A powerful antioxidant, it aids recovery from illness and injury. Most people have enough from a balanced diet; any excess is excreted.

Bach Rescue Remedy

What is it? The most popular of the 38 flower remedies developed by Dr Edward Bach early in the last century. A mixture of five essences: cherry plum for loss of control, clematis for unconsciousness, impatiens for stress, rock rose for terror, and star of Bethlehem for shock.

How much is it? £5.65 for 20ml

What does it do? Said to help with moderate anxiety, stressful situations, or to calm the user after serious news.

Does it work? Evidence shows it has no more than a placebo effect.

Arnica

What is it? Also known as leopard's bane, arnica montana is a perennial herb with a cluster of yellow flowers, native to central Europe and Asia.

How much is it? £3.95 for 30g

What does it do? Used as an ointment or tincture to relieve bruises or sprains.

Does it work?

Evidence for effectiveness is weak.