Are Herbal Supplements Safe? -- Arthur Presser, PharmD, DHPH

WebMD Live Events Transcript
Event Date: Wednesday, June 2, 2004

By Arthur Presser, PharmD, DHPh
WebMD Weight Loss Clinic

Millions of people take herbal supplements because they want to ingest something safe and healthy. But just because something is natural, is it safer than a synthetic drug? And exactly who is looking over the manufacturers' shoulders on your behalf? Supplement expert Arthur Presser, PharmD, DHPh, joined us on June 2, 2004, with some answers.

If you have questions about your health, you should consult your personal physician. This event is meant for informational purposes only.

Welcome to WebMD Live, Dr. Presser. How are herbal supplements regulated in the U.S.? Are they given the same level of scrutiny as prescription drugs?

No, of course not. Prescription drugs have the highest level of scrutiny because they're literally chemical poisons that we're using for their positive benefits against their negative benefits. They're used to treat diseases and conditions that must be diagnosed and monitored by physicians. The next level down would be over-the-counter drugs that are on the market for conditions that are self-diagnosable and self-limiting.

Herbs are considered dietary supplements, and basically part of the food chain. Prescription drugs, to come to market, must undergo hundreds of millions of dollars of clinical testing to prove their efficacy and measure their toxicity. Herbs are nature's medicines that have sometimes 5,000 years of historical use for many conditions. Only in recent times have universities and private industry taken these traditional uses and run clinical studies to determine how they might be working or have worked in the past and predict what they might be useful for in the future. However, they are still dietary supplements, and really are subject to claims that are just associated with structure and function of the human body.

You have to understand that there is a very strong political aspect to herbal medicine. Between 25% and 50% of pharmaceutical drugs on the market today are derived directly from, or from a model of, a plant chemical. This plant chemical cannot be used directly as it comes from nature because it cannot be patented and protected financially, so the chemical must be altered into a new entity, an analog, and then tested for efficacy and toxicity. If this new chemical works and isn't too poisonous, it is entered into the hundreds of millions of dollars of testing to bring a new drug to market.

The herbs in themselves, as whole herbs, are generally much milder, generally not toxic, take longer to work, and are much more complicated than pharmaceutical drugs. Pharmaceuticals are monostructures; that is they contain one single chemical. Herbs can contain hundreds and hundreds of chemicals, each doing something different in the bodies, oftentimes offsetting toxicities; that is if there is a chemical that might raise blood pressure there may be a secondary chemical that offsets chemical A's ability to act in this manner.

In terms of manufacturing, many medicinal herbs today are manufactured by pharmaceutically licensed laboratories. All herbs and dietary supplements must comply with government GMPs -- good manufacturing procedures. This is not to say that some companies don't use inferior ingredients.

But some herbals are more potent than some prescription drugs, aren't they? They are more likely to cause problems if taken incorrectly, I guess I should say.

I can't think of an herbal medicine that is stronger and more toxic than an equivalent pharmaceutical drug, unless you are considering strychnine or arsenic, which do occur in nature naturally. Certainly there are things like poison mushrooms, but I don't consider those medicinal. I'm working in the world of herbs that heal and herbs that are beneficial, not things that are poisonous.

How do we know that what is on the label is what is in the bottle with herbs? I've read that bottles of the same herb from different manufacturers can vary a lot. Why can't they ensure that the herbal supplements are pure and actually the strength claimed?

This aspect of commercially available herbal preparations is not well regulated. You can pick up two bottles of St. John's Wort, and unless you are buying from a reputable manufacturer you can be getting two completely different medicines. This is the greatest problem that faces complementary medicine today. As a health care professional, if I were to advise a patient with mild to moderate depression to take St. John's Wort, unless I named a specific brand, I would not be sure they were getting a good medicine.

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