The BBB suggests that consumers review claims themselves and ask for copies of clinical human studies that support any claims that products can treat or cure diseases or ailments. Any claims that a product can cure or treat diseases or ailments should be reported to the BBB immediately.
Federal law through the Food and Drug Administration (FDA) allows for some claims, if scientific evidence is available. The FDA does not review or authorize claims. You will note that dietary supplement companies all have a disclaimer on their sites which states "This statement has not been evaluated by the FDA. This product is not intended to diagnose, treat, cure, or prevent any disease." This statement is required by law and is used to alert the public that the product has not been reviewed, essentially buyer beware.
For more information about dietary/nutritional claims check out these online resources:
U. S. Food and Drug Administration - Center for Food Safety and Applied Nutrition: http://www.cfsan.fda.gov/~dms/ds-oview.html
Federal Trade Commission - http://www.ftc.gov/bcp/menus/consumer/health/drugs.shtm
Mayo Clinic, Rochester, Minnesota - http://www.mayoclinic.com/health/supplements/CM00016
National Library of Medicine and National Institutes of Health - www.pubmed.gov
National center for Complementary and Alternative Medicine - www.mccam.nih.gov