Journal of General Internal Medicine

, Volume 23, Issue 6, pp 854–859 | Cite as

Herbal Medicine in the United States: Review of Efficacy, Safety, and Regulation

Grand Rounds at University of California, San Francisco Medical Center
  • Stephen BentEmail author
Clinical Review



Herbal products have gained increasing popularity in the last decade, and are now used by approximately 20% of the population. Herbal products are complex mixtures of organic chemicals that may come from any raw or processed part of a plant, including leaves, stems, flowers, roots, and seeds. Under the current law, herbs are defined as dietary supplements, and manufacturers can therefore produce, sell, and market herbs without first demonstrating safety and efficacy, as is required for pharmaceutical drugs. Although herbs are often perceived as “natural” and therefore safe, many different side effects have been reported owing to active ingredients, contaminants, or interactions with drugs.


Unfortunately, there is limited scientific evidence to establish the safety and efficacy of most herbal products. Of the top 10 herbs, 5 (ginkgo, garlic, St. John’s wort, soy, and kava) have scientific evidence suggesting efficacy, but concerns over safety and a consideration of other medical therapies may temper the decision to use these products.


Herbal products are not likely to become an important alternative to standard medical therapies unless there are changes to the regulation, standardization, and funding for research of these products.


herbal medicine efficacy safety regulation 



The author thanks Erin Hartman, MS, Department of Medicine, University of California, San Francisco, for her editorial assistance on this manuscript. Dr. Bent had full access to all of the data in this presentation and takes responsibility for the integrity of the data and the accuracy of the presentation. This work was supported by Grant Number 1 K08 ATO1338-01 (Dr. Bent) from the National Center for Complementary and Alternative Medicine (NCCAM). The funding organization had no role in the design and conduct of the review; the collection, management, analysis, and interpretation of the data, or the preparation, review, or approval of the manuscript.

Conflict of Interest Statement

Dr. Bent previously served as an expert witness for plaintiffs in cases of injury related to the use of ephedra (last case completed in July 2004).


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Copyright information

© Society of General Internal Medicine 2008

Authors and Affiliations

  1. 1.Osher Center for Integrative MedicineUniversity of CaliforniaSan FranciscoUSA
  2. 2.Department of MedicineSan Francisco Veterans Affairs Medical CenterSan FranciscoUSA
  3. 3.Department of Epidemiology and BiostatisticsUniversity of CaliforniaSan FranciscoUSA
  4. 4.San Francisco VAMCSan FranciscoUSA

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