Substances such as herbal remedies and vitamins are sometimes marketed as "dietary supplements", which is a legal classification for a particular kind of foodstuff.
Since the Dietary Supplement Health and Education Act of 1994, supplement manufacturers can make general claims about the health-promoting properties of their products without the kind of rigorous standards that would be required to establish safety and effectiveness if the same product were marketed as a drug or a food additive.
This means that dietary supplements vary widely in safety and in effectiveness; in some cases, there is little or no scientific evidence to support manufacturers' claims.
The Mayo Health Clinic (http://www.mayohealth.org) maintains a current list of information about dietary suppelements.
Article : "GINKGO"
by Catherine E. Myers. Copyright © 2006 Memory Loss and the Brain