Hundreds of botanicals sold in the U.S. have either not been tested for effectiveness and safety or found not to work. Some St. John's wort is standardized for a chemical called hypericin. But hypericin is not linked to the antidepressant activity of the plant. Many other substances in the herb have been show to have an effect on the brain. There are, undoubtedly, many ethical suppliers of these products, but there is no way for consumers to know what they are getting under current regulations.
Plants contain lots of biologically active ingredients.
Most are defenses against attack by insects or animals. There is no reason to think that all of these will be safe for people or have benefits in treating disease. Now when nutrition news gets confusing, there IS a place to go to get the real story. Our FREE daily email newsletter, Nutrition News Focus, helps you make sense of it all. It's written by Dr. David Klurfeld, Chairman and Professor of the Department of Nutrition and Food Science at Wayne State University.