Americans spend nearly $15 billion yearly on herbal supplements despite clinical studies that show that many of the most popular ones such as ginkgo biloba, echinacea and St. John’s wort do not live up to their claims.

The Food and Drug Administration only loosely regulates dietary supplements, unlike pharmaceuticals, which undergo years of testing and clinical trials before being approved for sale.

The FDA does not test dietary supplements. It leaves it up to manufacturers to make sure that a supplement is safe and meets claims of purity, composition and efficacy. It does not require supplement manufacturers to present any information about how they do this.

Recent studies by several independent researchers have found wide discrepancies in the composition and dosage of supplements compared with the information given on their labels.

Supplement manufacturers are not allowed to make claims about curing, treating or preventing specific ailments, but product labels can make general claims about potential improvements in bodily function such as "aids digestion" or "boosts brain function."

There is a growing concern that with the proliferation of dietary supplements, the claims and warnings get lost in the wording on the product labels since the distinctions between body-function statements and specific treatment indications may be too subtle to help all consumers.

"Helps promote normal heart function" may sound a lot like "helps prevents heart disease" to many shoppers.

On May 26 the U.S. Government Accountability Office reported to Congress the results of an investigation that revealed how these loose regulations, along with questionable and aggressive sales tactics, are putting the health of consumers at risk.

In its investigations, the GAO used undercover shoppers to ask common questions of supplement retailers. Shoppers older than 65 were chosen because many seniors take prescription medicines that pose a danger when taken in combination with supplements. Many over-the-counter herbs are known to present more of a health risk than some prescription drugs that are regulated by the FDA.

Some of the questions asked: Is ginkgo safe to take with aspirin? Can ginseng help prevent cancer? Should I replace prescription blood pressure medication with garlic?

These questions received overwhelming "yes" answers from supplement sales staff, although they are dangerous, according to the National Institute of Health. Both the FDA and the Federal Trade Commission found the retail practices "improper and likely in violation of statutes and regulations," although the majority of the sales people did not know they were in violation of either the law or best practices.

The concern in the minds of health experts is not whether consumers are willing to buy products of questionable efficacy, but whether taking the supplements can be harmful to one’s health when taken alone or with prescription medications.

Many supplements tested for this GAO investigation contained traces of one or more hazardous compounds, steroids and active pharmaceuticals, bringing into question whether leaving the fox to guard the chickens is in the best interest of consumer health.