St. John’s Wort Has Its Own Set of Problems

St. John’s wort for the treatment of depression sounds like a great alternative to prescription drugs with their high costs, relatively lengthy kick-in time and sometimes major side effects. After all, it’s been used for centuries, and not only that, it’s also an herb--a natural product--and natural products are safe. Right? Wrong.

The assumption that natural equals safe, and that long-term use enriched by many anecdotal reports means effective, fall among the most dangerous beliefs we hold dear. Back in colonial times, bloodletting therapy, which probably killed George Washington, was an example of the many medical methods made no less deadly by virtue of its entrenched respectability. Many natural products or their components are poisonous.

Understanding that medicinal herbs are not just plants with healing properties, but dilute (or weak) prescription medications helps us adopt a more realistic perspective. Like pharmaceuticals, natural products such as St. John’s wort are drugs that can harm as well as help, create adverse effects, and interact with other medicines. Unlike pharmaceuticals, however, herbal remedies in this country are not subject to oversight by the Food and Drug Administration. As such, we don’t always know what’s in the bottle.

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St. John’s wort has been studied extensively in Europe, where it is prescribed and treated as a drug. Simultaneous analyses of multiple European studies indicate that St. John’s wort effectively treats mild and moderate depression. We’ve found it helpful here, too. Americans eagerly seek this over-the-counter remedy for depression, which is the leading cause of disability in this country. Retail sales climbed by almost 3,000% during a recent single year.

As Americans in ever larger numbers used this herbal remedy over time, reports of problems not captured in Europe’s relatively brief studies began to surface. This cost-effective, readily available therapy, this natural, yellow bloom that vanquished our dark moods, turns out to create serious problems when taken with other medications.

To hammer home the point that herbs are not always the harmless, natural products we wish them to be, St. John’s wort activates certain enzymes in the liver that decrease blood levels of some important medications. Through this action, St. John’s wort reduces the amount of drug available in the body to treat HIV infections, to thin the blood and to keep heart transplants from being rejected. It also reduces the effectiveness of anti-seizure drugs, birth control pills, antidepressants and chemotherapy.

Potential consequences are serious. A few months ago, the FDA issued a public health alert about the dangers of taking St. John’s wort with other medications.

If you are healthy and on no other medications, St. John’s wort probably will help relieve your depression and cause no major difficulties. But if you are taking any medication, stay on the safe side and assume that this otherwise helpful herb could cause serious harm by impeding the action of that medication. When considering St. John’s wort or the use of any herbal remedy, consider what the capsule contains, potential interactions, possible side effects and whether information on effectiveness exists.

What’s in the capsule? Check whether the capsule contains enough of the right ingredients and whether it includes contaminants or unwanted matter. St. John’s wort usually is standardized for one of its chemicals, hypericin. But it turns out that other of the herb’s ingredients, as yet undocumented, reduce depression. Hypericin does not.

While herbal product companies may tout “standardized” to enhance the image of their products as safe and reliable, the word has little meaning with St. John’s wort and other herbs. Moreover, studies of the amount of active ingredient present in samples of the same product from the same manufacturer show wide variations.

Contamination, from soil compounds such as heavy metals, or with other botanical or animal products, remains a problem--another artifact of the absence of regulation. Purity and consistency are not current hallmarks of herbal remedies.

Drug interactions. Possible with almost any prescription medication. Just as interactions between drugs occur, so too herbs (remember, they are dilute drugs) are likely to interact with some medications. Because not all herb-drug interactions are known, it’s best to err on the side of safety and avoid herbal remedies if you are on prescription medications. And be sure to check with your doctor.

Side effects. St. John’s wort has caused gastrointestinal disturbances, allergic reactions, dizziness, fatigue, dry mouth, confusion and over sensitivity to light. Because all herbs and other food supplements are exempt from government regulation and control, these dangers are not likely to be listed on the label. Herbal remedy labels may make almost any claim short of curing disease. Reporting side effects is not mandated.

Effectiveness information. The U.S. government classifies herbal remedies as food supplements. Unlike foods or drugs, food supplements are not regulated by any federal agency under a law passed by Congress in 1994, and manufacturers are not required to evaluate or note safety or efficacy data. Studies conducted elsewhere, such as the European research on St. John’s wort, may not meet the rigorous standards applied to drugs in the U.S.

An ongoing study supported by the National Institutes of Health will provide missing information about the long-term effects of St. John’s wort, whether it reduces severe depression in addition to mild or moderate depression, and how it fares in comparison to prescription medications for depression.

As increasing numbers of well-known U.S. and European companies produce and market herbal remedies, more and better research, accurate claims and consistent, pure, effective products will ensue. Until then, seek information about herbs on objective Web sites or publications that do not sell botanical products.

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This week we begin a new monthly column on alternative and complementary medicine to help consumers evaluate herbal remedies, dietary supplements and other unconventional therapies. The column’s author is Barrie R. Cassileth, chief of Integrative Medicine Service at Memorial Sloan-Kettering Cancer Center in New York. Cassileth was a founding member of the advisory council to the National Institutes of Health’s Office of Alternative Medicine, now the National Center for Complementary and Alternative Medicine.