How Safe Are Herbal Supplements?

The shelves of your local supermarket and drugstore are probably brimming over with a bewildering array of dietary supplements and herbal remedies. Many are advertised to have benefits that will improve your sex life, your memory or your figure.

But how real are these claims? And how safe are the ingredients in these supplements?

According to many industry experts, the problems with herbal supplements are just beginning to be understood.

"One out of four has some sort of problem," said Dr. Tod Cooperman, physician and president of, an independent laboratory that tests dietary supplements. "People should keep that in mind."

Toxic Contaminants in 'Natural' Products

In many cases, Cooperman's group has found that some name-brand supplements contain only a fraction of the ingredient on their labels -- if any at all.

"Some have none, some have 80 percent, some have 20 percent," Cooperman said.

Another problem with supplements involves contamination. In two separate cases last month, pesticide residue was found in a batch of ginseng at a distributor in New Jersey, and toxic heavy metals like mercury, lead and arsenic were discovered in herbal supplements on sale in stores in the Boston area.

Researchers have also found significant amounts of Viagra and Cialis, prescription medicines for treating erectile dysfunction, in "natural" sexual enhancement supplements. "There are increasing instances of them being spiked with pharmaceutical products to make them more effective," said Cooperman.

Worrisome Combinations of Medications

Besides the concerns over the safety of individual products, many doctors warn their patients about the way herbal medications can interact with prescription medication.

"Most of the risks aren't known," said Dr. Neil Brooks, a family physician in Vernon, Conn. "What they're doing is adding chemicals to their bodies and we don't know what the effects are, independently or in combination."

"I had a patient the other day who had at least 12 things she was taking," Brooks said.

But many patients choose not to reveal to their doctors the supplements they're taking. In a report released today, the Institute of Medicine states that fewer than 40 percent of patients fully disclose to their doctors what supplements they use.

The IOM report, entitled "Complementary and Alternative Medicine (CAM) in the United States," also notes that users of alternative medicines like dietary supplements generally use more than one type and use them in combination with more conventional medical treatments.

About 40 percent of Americans routinely use one or more dietary supplements. By most estimates, sales of supplements in the United States alone have created a $19 billion industry.

Some Benefits Are Undisputed

Even the most hardened skeptics understand that many dietary supplements have benefits that are universally accepted.

"Vitamins and minerals at RDA [recommended dietary allowance] levels are needed to prevent deficiencies," said Cooperman. "Some of the greatest examples are calcium, folic acid and iron."

Those three supplements are used to prevent osteoporosis, pregnancy complications and blood deficiencies, respectively.

"For nutritional supplements, there are a wide variety of benefits," said Annette Dickinson, nutritionist and president of the Council for Responsible Nutrition, a trade association of dietary supplement manufacturers.

"Almost everybody's diet falls short somewhere," said Dickinson.

FDA Regulation Is Limited

Dickinson also agrees that some unscrupulous manufacturers have given the entire supplement industry a black eye. One egregious example, she says, occurred with the efforts to stop the sale of supplements containing ephedra, a compound linked to several deaths nationwide.

"The controversy over ephedra dragged on years longer than it should have," Dickinson said. "The most we can do is petition the [enforcement] agencies to take action."

In 2004, sales of the substance were banned by the Food and Drug Administration, following their review of ephedra's safety and effectiveness from clinical studies and numerous reports of the compound's adverse effects.

But the length of time it took before ephedra was removed from store shelves -- and the deaths that occurred before it was banned -- highlight the weaknesses in the regulatory environment under which the supplement industry operates.

The Dietary Supplement Health and Education Act, signed into law in 1994, determined that supplements should be regulated not like drugs, but like foods. By making this determination, according to today's IOM report, supplement manufacturers were exempt under DSHEA from conducting any safety or efficacy testing.

To many industry critics, the net effect of DSHEA has been to limit the FDA's role to a reactive, post-market role. Only after the FDA determines that a substance, when used as recommended, presents a risk to consumers can the agency remove it from the market.

And because manufacturers are not required to report adverse effects from a substance, the burden for proving that a substance is harmful falls to the FDA.

'The Body Rule'

But Dickinson and others believe the fallout from the ephedra controversy has made the regulatory framework for supplement manufacturers more robust.

"For the first six or eight years after DSHEA was passed, the FDA didn't do much to implement the law," Dickinson concedes. But then came the ephedra controversy.

"It used to be called the 'body rule,' " says ConsumerLab's Cooperman, referring to the number of deaths that were needed to prompt an investigation from the agency. "You needed to have a lot of adverse effects before you could go looking for a cause. ... But ephedra has emboldened the FDA to act more quickly."

Now, Dickinson says, "the FDA is taking strong enforcement action to fully implement DSHEA" -- something she says her group welcomes. She believes criticisms that the supplement industry is unregulated are entirely unfair.

Advice to Consumers

But some critics are not mollified by these assurances.

"As I see it, the main effect of the DSHEA has been to allow supplement companies to run rampant and make claims that are not substantiated," said Dr. Kevin Scott Ferentz, residency director in the Department of Family Medicine at the University of Maryland School of Medicine in Baltimore.

"They sell products that do not contain what they are supposed to. They do not have efficacy data, safety data, quality control data or anything that any pharmaceutical product in America must have," he said. "There are few, if any, supplements that have a data base that is sufficient to recommend their use."

In almost all cases, experts advise consumers to approach dietary supplements with caution -- and with reliable information.

"Consult with your physician," said Brooks. "And use reliable sources for information. We have people come in with all sorts of Internet ads."

"Consumers need to inform themselves about what they're using," said Dickinson. "The primary risk is from their own ignorance."

This is especially true for patients taking prescription drugs. "If they're taking other medications, they should check with their primary care physician just in case there are contraindications," said Cooperman.

And Ferentz notes that no dietary supplement should be considered a panacea. "People want to think there is a magic pill out there for everything," he said. "They assume that because something is a 'natural supplement' that it has to be safe and effective. Nothing could be further from the truth."