CHAPEL HILL, N.C. (AP) _ Physicians need more training in herbal medicine, and more research into the remedies themselves is needed, speakers at an international conference said.

Doctors in some European countries are trained in herbal remedies, while such training is rare in the United States, scientists said Thursday at the conference on safety and effectiveness of herbs.

``People seek a cure for something we haven't been able to provide ... so they take the action by themselves,'' said Dr. Felix Stickel of the University of Erlangen and Salen Medical Center in Heidelberg, Germany.

``The physicians have to become aware of the needs as well as the scientific background of these herbs.''

Herbal medicines are a $4 billion-a-year industry in the United States, where an estimated one-third of the adult population uses them. The remedies are sold as food rather than regulated as drugs.

Although herbal remedies generally are safe _ one, however, can cause severe liver damage _ more basic research is needed, scientists said.

``Is it a waste of money? Is it dangerous? We don't have enough data to know,'' said Lenore Arab, professor of epidemiology and nutrition at the University of North Carolina-Chapel Hill, which sponsored the conference.

One of the herbs discussed at the meeting was comfrey, a root-derived remedy that is widely available in the United States and is taken for its purported anti-inflammatory and antibacterial properties.

Stickel said the herb should be restricted as it is in Germany and Canada.

Not only are the effects of comfrey unproven in limited clinical studies, it appears to destroy small veins in the liver and can result in abdominal pain, liver enlargement and liver failure, he said.

Speakers at the conference said many other herbal remedies appear no more dangerous than aspirin, but far less understood.

``We need to convince the producers to put some money into research on these products,'' said Varro Tyler, an herbal medicine expert at Purdue University.

Speakers covered the most popular remedies: St. John's wort for depression, garlic for cholesterol and anticancer uses, gingko biloba for treating dementia, ginseng as a tonic, saw palmetto for urological problems, echinacea for colds and to enhance the immune system and feverfew to treat migraine headaches.

Tyler said a system should be developed to regulate herbal remedies without the stringent requirements for synthetic drugs enforced by the U.S. Food and Drug Administration.

The FDA issued new rules in January to liberalize the claims that can be made about the herbal remedies, but the conference participants said what herb users need is more information.

``There is absolutely no way that consumers can be assured that what is on the label is actually in the package, other than the reputation of the producer,'' Tyler said.