Little Public Protection
In the United States, herbs intended for preventive or therapeutic use would be regulated as drugs under federal laws. To evade the law, these products are marketed as "foods" or "dietary supplements" without health claims on their labels. Since these are not regulated as drugs, no legal standards exist for their processing, harvesting, or packaging. In many cases, particularly for products with expensive raw ingredients, contents and potency are not accurately disclosed on the label. Many products marked as herbs contain no useful ingredients, and some even lack the principal ingredient for which people buy them. Surveys have found have found that the ingredients and doses of several products varied considerably from brand to brand.
A Good Housekeeping Institute analysis of six widely available St. John's wort supplement capsules and four liquid extracts revealed a lack of consistency of the suspected active ingredients, hypericin and pseudohypericin. The study found:
A 17-fold difference between the capsules containing the smallest amount of hypericin and those containing the largest amount, based on manufacturer's maximum recommended dosage.
A 13-fold difference in pseudohypericin in the capsules.
A 7-to-8-fold differential from the highest to the lowest levels of liquid extracts [1].
A similar investigation by the Los Angeles Times found that 7 of 10 St. John's wort products contained between 75% and 135% of the labeled hypericin level, and three contained no more than about half the labeled potency [2].
Researchers at the University of Arkansas who tested 20 supplement products containing ephedra (ma huang) found many differences in alkaloid content from product to product and between two lots of the same product. Half the products exhibited discrepancies of 20% or more between the label claim and the actual content, and one product contained no ephedra alkaloids [3]. Ephedra products are marketed as "energy boosters" and/or "thermogenic" diet aids, even though no published clinical trials substantiate that they are safe or effective for these purposes. The researchers also noted that hundreds of such products are marketed and that their number exceeds that of conventional prescription and nonprescription ephedra products, which are FDA-approved as decongestants
The April 2000 issue of D Magazine reported that—at its request—a leading laboratory had tested five brands of DHEA, ginger, ginkgo biloba, ginseng, melatonin, saw palmetto, St. John's wort, and milk thistle purchased at five stores in the Dallas area. The ginger and melatonin products contained the stated amounts, but 10 of the other 30 products did not, and a few products had capsules that easily fell apart [4].
In October 2003, the AMA Archives of Internal Medicine reported the results of a survey of herbal products at twenty retail stores in and around Minneapolis. The chosen herbs were echinacea, St. John's wort, ginkgo biloba, garlic, saw palmetto, ginseng, goldenseal, aloe, Siberian ginseng, and valerian. The authors noted that 43% of 880 products were labeled with the ingredients and dosage that had used in published studies of the ingredients. The actual ingredients were not measured, but the survey indicated that many manufacturers failed to formulate their products to correspond with available research data [5].
In 2010, ConsumerLab told me that nearly half of the herbal products they had tested for quality had failed their evaluations. The reason for failure included too little or too little of the main ingredient, potentially dangerous or illegal ingredients, contamination with heavy metals, "spiking" with unexpected ingredients, and misleading or incomplete product information.
In 2013, Canadian researchers used DNA barcoding (a type of genetic "fingerprinting") to test 44 products from 12 companies and found that 59% of the products contained ingredients not listed on the label, 30 of the 44 products had ingredient substitutions, and some contained contaminants that posed health risks to users [6].
Some manufacturers are trying to develop industrywide quality-assurance standards, but possible solutions are a long way off.
Regulation Is Minimal
The Dietary Supplement Health and Education Act of 1994 included herbal products in its definition of "dietary supplements," even though herbs have little or no nutritional value. (The bill was spearheaded by the health-food industry in order to weaken FDA regulation of its products.) Herbal or other botanical ingredients include processed or unprocessed plant parts (bark, leaves, flowers, fruits, and stems) as well as extracts and essential oils. They are available as teas, powders, tablets, capsules, and elixirs, and may be marketed as single substances or combined with other herbs, vitamins, minerals, amino acids, or non-nutrient ingredients. Products containing multiple herbal ingredients may produce adverse effects that are impossible to predict. A 1999 survey by Prevention magazine found that 12% of herbal remedy users reported adverse reactions [7].*
The manufacture of prescription and over-the-counter drugs is closely regulated by the FDA, But herbal products are not [8].
Even the fact that an herb is known to be toxic does not ensure its removal from the marketplace. When the FDA concludes that an herb is dangerous, it usually issues a warning rather than a ban. Several years ago, the FDA Center for Food Safety and Applied Nutrition maintained a database of reports the FDA has received of adverse events associated with the use of dietary supplements and herbal products. However, the database is no longer posted because the FDA could not be certain that the reported problems were caused by the products or had occurred for other reasons.
http://www.quackwatch.org/01QuackeryRel ... herbs.html 
) 
