Bloodied but unbowed, Jenny Seagrove is still in fighting mode despite last month’s humiliating defeat at the High Court as she attempted to overturn a ban on kava, an ancient herbal remedy for anxiety.

“The battle has been lost but the war continues,” the actress declares angrily. “It’s absolutely unjustified to ban it and just symptomatic of the nanny state that we now live in.”

The ban was imposed a year ago after reports that 70 users around the world suffered liver damage, including three in the UK. Seven cases required liver transplants and four died, including two of those who received new livers. So great is the concern that Germany, Switzerland, France, Canada and, most recently, the United States have taken action to limit its use or prohibit its sale.

Convinced that an outright ban was a gross overreaction in a world where all medicines carry risks, Seagrove joined forces with the National Association for Health Stores (NAHS) in challenging the Government, arguing that the dangers of kava have been greatly exaggerated.

“Kava is a 2,000-year-old remedy. Millions of people have taken it without any harm,” she says. “The problem is that there is a risk if it is used with alcohol. The people who died were very old and some already had cirrhosis of the liver, but that wasn’t taken into consideration. I’m not somebody who wants something on the market that’s going to be dangerous to people. All it needs is better labelling.”

The case became a cause célèbre for the herbal industry, which has lost a market worth £7.5 million. It boasted the support of several academics, including Professor Edzard Ernst of Exeter University, Britain’s only professor of complementary medicine, who argued that the risk of liver damage was no worse than that of Valium.

Seagrove, 46, became a celebrity figurehead for the campaign, insisting that she depended on the herb to help her sleep during stressful times in her career. Currently appearing in The Secret Rapture at the Lyric Theatre, in London, she says: “I have used kava for about five years. I even give it to my dog, Kizzy, on bonfire night. It’s very gentle, but it helps me sleep when I’m stressed, especially leading up to an opening night.”

Unlike some herbal remedies, kava has proven medical benefits: placebo-controlled trials have shown that it is useful for relieving anxiety. The Polynesian shrub, whose Latin name means “intoxicating pepper”, is the basis of the national drink of Fiji and Tonga. In its traditional form, it is prepared by grating or pounding the fresh root and mixing it with cold water or coconut milk.

Seagrove, who lives in Little Venice, northwest London, with the theatre impresario Bill Kenwright, and who once lived with the film director Michael Winner, adds: “Peanuts, tobacco and alcohol kill large numbers of people yet they are not banned. HRT has been linked to cancer, but it isn’t banned. The whole thing is out of proportion. The principle that I’m fighting for is to be allowed to choose, as long as I am aware of the possible risks.

“People are disillusioned with the medical profession which is why they are turning to herbal remedies. Problems sometimes arise when there are a small minority of herbal products which lack quality. If there was better labelling and spot checks, rather like the doping tests on footballers, it would help.”

She criticises new EU directives requiring licensing, registration and uniform manufacturing standards for herbal medicines which, many would argue, would achieve precisely the controls she deems necessary. “The EU directives are a catastrophe. We are going to lose so many products,” she insists, echoing the views of much of the complementary health lobby which is anxious to protect a market worth £130 million.

Estimates of the impact of this new legislation vary, but it will undoubtedly cause problems for small British supplement companies as they are forced to reformulate entire ranges and invest massively in applying for new product licences.

At the High Court last month, Mr Justice Crane agreed that the consultation process in deciding to ban kava had been “procedurally flawed” but this did not justify ordering fresh consultations.

Ralph Pike, director of the NAHS which represents 420 independent health stores, is anxiously awaiting a further hearing in March to decide whether his organisation will have to pay an estimated £200,000 in legal costs for both parties in the case. He says: “All we wanted was a rerun of the consultation process to explore the evidence more thoroughly. The judge agreed that the process had been done wrongly, but said the decision to ban still stands. We hope this will be grounds for an appeal.”

As she waits her next day in court, Seagrove — who also takes echinacea and gingko biloba but would never touch an aspirin — says that she has not found an effective replacement for kava. “Valerian never worked for me,” she sighs.

“I have had lots of wonderful letters of support from people. Some of them have even sent me their last capsules of kava — although I suspect that a lot of it, sadly, is well past its sell-by date.”

• Kava is not the only herbal medicine considered potentially harmful. St John’s wort, taken as an antidepressant, can adversely affect Aids drugs, birth-control pills and chemotherapy, says the New England Journal of Medicine

Click here to read Body&Soul's Complementary Therapists Guide 2004