A meta-list of resource links compiled by the USDA (May 2011)

http://fnic.nal.usda.gov/nal_display/index.php?info_center=4&tax_level=2&tax_subject=274&topic_id=1331

Medline (a service of the US National Library of Medicine/NIH) list of herbal supplements with summaries of known use, effectiveness and risk.

http://www.nlm.nih.gov/medlineplus/druginfo/herb_All.html

FDA consumer updates on dietary supplements http://www.fda.gov/ForConsumers/ConsumerUpdates/ucm153239.htm

The University of Maryland Medical Center Alternative Medicine Index

http://www.umm.edu/altmed/

"Herbal supplements: What to know before you buy" from the Mayo Clinic

http://www.mayoclinic.com/health/herbal-supplements/SA00044