Table 1.

The Ten Most Commonly Used Herbal Medicines in the United States

Herb	Percent use in U.S.*	Common use†	Scientific evidence for efficacy‡	Safety
Echinacea	7.0	Upper respiratory tract infection	Inconclusive9	Side effects similar to placebo9
Ginseng	4.2	Physical and cognitive performance	Inconclusive12	Limited data; hyperactivity and restlessness in case reports12
Ginkgo biloba	3.7	Dementia	Likely Effective13	Side effects similar to placebo;16 case reports of bleeding17
		Claudication	Likely effective15
Garlic	3.4	Hypercholesterolemia	Likely Effective18	Mild gastrointestinal side effects and garlic odor;18 case reports of bleeding20,21
St. John’s wort	2.1	Depression	Likely Effective for mild–moderate depression22,23	Numerous reports of drug interactions26
Peppermint	2.1	Upset stomach / irritable bowel syndrome	Inconclusive27	Limited data, but side effects appear to be mild27
Ginger	1.8	Nausea	Inconclusive28	No known side effects5
Soy	1.7	Menopausal symptoms	Not effective29	Concerns regarding long-term estrogenic effects29
		Hypercholesterolemia	Effective30
Chamomile	1.5	Insomnia / gastrointestinal problems	No high-quality data	Rare allergic reactions31
Kava kava	1.2	Anxiety	Likely Effective32	Case reports of severe hepatotoxicity33

*Percents are based on estimates from a 2002 National Health Interview Study, age adjusted to the year 2000 U.S. Standard Population¹

^†Common use was determined from herbal medicine textbooks.^5,31,57

^‡Scientific evidence is based on conclusions from recently published systematic reviews.³⁶