Jan. 18, 2002 -- A European study suggests that an obscure herbal supplement may be as powerful as the most effective antihistamine for treating the symptoms of hay fever, but an expert warns that it is way too soon to head to the health food store for it.

Researchers in Switzerland report that seasonal allergy patients treated with an extract of the botanical butterbur reported symptom relief similar to patients treated with the antihistamine cetirizine, known by the brand name Zyrtec. Butterbur -- also known as butter dock, bog rhubarb, and exwort -- grows in Europe, northern Africa, and southwestern Asia.

The 125 patients participating in the study were treated with either butterbur or cetirizine for two weeks and then were evaluated though questionnaires. Patients reported similar symptom relief with both treatments, and there were equal numbers of adverse reactions in both groups. Those treated with the antihistamine did report more drowsiness, however.

"Butterbur was well tolerated and did not have the sedative effects associated with antihistamines," the authors wrote in the Jan. 19 issue of the British Medical Journal. "We believe butterbur should be considered for treating seasonal allergic rhinitis, particularly in cases where the sedative effects of antihistamines need to be avoided."

But a California rheumatologist who has spent years searching for effective alternative therapies to treat allergies and asthma is not impressed by the study. M. Eric Gershwin, MD, of the University of California at Davis, says it does little to convince him that butterbur extract is either effective or safe for treating hay fever. Gershwin is a founder of The Center for Complementary and Alternative Medicine Research in Asthma, Allergy, and Immunology at UC Davis.

"Butterbur has been around forever, and it has been used for everything from treating migraines to urinary symptoms to asthma," Gershwin tells WebMD. "And a few years ago, there was a study suggesting that it inhibits testosterone. But the fact is, very little is known about its constituents and interactions with other drugs."

Gershwin says the European study was poorly designed and failed to answer basic questions needed to prove the efficacy and safety of butterbur extract. The European researchers acknowledge that more studies need to be done.

"There is a tendency to think that if something is natural, it is safe," Gershwin says. "But hemlock is natural. Socrates drank hemlock and died. Just because something is natural doesn't mean it is good for you."

So far, Gershwin says, studies evaluating alternative approaches to the treatment of allergies and asthma have proven disappointing. He adds that the best strategies for dealing with seasonal allergies are still avoiding environmental triggers and taking antihistamines.

"All kinds of things have been tried for hay fever, but nothing looks very promising," he says.