|When Considering Herbal Supplementation, Consider Safety Too
Article Courtesy of National Center for Complementary and Alternative Medicine
|Herbal Supplements: Consider Safety, Too
Herbal supplements are a type of dietary supplement (see the box below) that contain herbs, either
singly or in mixtures. An herb (also called a botanical) is a plant or plant part used for its scent, flavor,
and/or therapeutic properties.
Many herbs have a long history of use and of claimed health benefits. However, some herbs have
caused health problems for users. This fact sheet contains points you should consider for your safety if
you use, or are thinking about using, herbs for health purposes. It does not discuss whether herbs work
for specific diseases and conditions (for science-based information on that topic, see "For More
About Dietary Supplements
Dietary supplements were defined in a law passed by Congress in 1994. A dietary supplement must
meet all of the following conditions:
It is a product (other than tobacco) intended to supplement the diet, which contains one or more of the
following: vitamins; minerals; herbs or other botanicals; amino acids; or any combination of the above
It is intended to be taken in tablet, capsule, powder, softgel, gelcap, or liquid form.
It is not represented for use as a conventional food or as a sole item of a meal or the diet.
It is labeled as being a dietary supplement.
It's important to know that just because an herbal supplement is labeled "natural" does not mean it is
safe or without any harmful effects. For example, the herbs kava and comfrey have been linked to
serious liver damage.
Herbal supplements can act in the same way as drugs. Therefore, they can cause medical problems if
not used correctly or if taken in large amounts. In some cases, people have experienced negative effects
even though they followed the instructions on a supplement label.
Women who are pregnant or nursing should be especially cautious about using herbal supplements,
since these products can act like drugs. This caution also applies to treating children with herbal
It is important to consult your health care provider before using an herbal supplement, especially if you
are taking any medications (whether prescription or over-the-counter). Some herbal supplements are
known to interact with medications in ways that cause health problems. Even if your provider does not
know about a particular supplement, he can access the latest medical guidance on its uses, risks, and
If you use herbal supplements, it is best to do so under the guidance of a medical professional who has
been properly trained in herbal medicine. This is especially important for herbs that are part of an
alternative medical system (see the box below), such as the traditional medicines of China, Japan, or
Alternative medical systems are built upon complete systems of theory and practice, and have often
evolved apart from and earlier than the conventional medical approach used in the United States. To find
out more, see NCCAM's fact sheet "What Is Complementary and Alternative Medicine?"
In the United States, herbal and other dietary supplements are regulated by the U.S. Food and Drug
Administration (FDA) as foods. This means that they do not have to meet the same standards as drugs
and over-the-counter medications for proof of safety, effectiveness, and what the FDA calls Good
The active ingredient(s) in many herbs and herbal supplements are not known. There may be dozens,
even hundreds, of such compounds in an herbal supplement. Scientists are currently working to identify
these ingredients and analyze products, using sophisticated technology. Identifying the active
ingredients in herbs and understanding how herbs affect the body are important research areas for the
National Center for Complementary and Alternative Medicine.
Published analyses of herbal supplements have found differences between what's listed on the label
and what's in the bottle. This means that you may be taking less--or more--of the supplement than what
the label indicates. Also, the word "standardized" on a product label is no guarantee of higher product
quality, since in the United States there is no legal definition of "standardized" (or "certified" or "verified")
Some herbal supplements have been found to be contaminated with metals, unlabeled prescription
drugs, microorganisms, or other substances.
There has been an increase in the number of Web sites that sell and promote herbal supplements on
the Internet. The Federal Government has taken legal action against a number of company sites
because they have been shown to contain incorrect statements and to be deceptive to consumers. It is
important to know how to evaluate the claims that are made for supplements. Some sources are listed
For More Information
The NCCAM Clearinghouse provides information on CAM and on NCCAM. Services include fact sheets,
other publications, and searches of Federal databases of scientific and medical literature. Publications
include "Are You Considering Using Complementary and Alternative Medicine (CAM)?" and "10 Things
To Know About Evaluating Medical Resources on the Web." The Clearinghouse does not provide
medical advice, treatment recommendations, or referrals to practitioners.
U.S. Food and Drug Administration (FDA)
Center for Food Safety and Applied Nutrition
Web site: www.cfsan.fda.gov
Toll-free in the U.S.: 1-888-723-3366
Information includes "Tips for the Savvy Supplement User: Making Informed Decisions and Evaluating
Information" and updated safety information on supplements. If you have experienced an adverse effect
from a supplement, you can report it to the FDA's MedWatch program, which collects and monitors such
information (1-800-FDA-1088 or www.fda.gov/medwatch).
Office of Dietary Supplements (ODS), NIH
Web site: ods.od.nih.gov
ODS supports research and disseminates research results on dietary supplements. It produces the
International Bibliographic Information on Dietary Supplements (IBIDS) database on the Web, which
contains abstracts of peer-reviewed scientific literature on dietary supplements.
CAM on PubMed
Web site: www.nlm.nih.gov/nccam/camonpubmed.html
CAM on PubMed, a database on the Web developed jointly by NCCAM and the National Library of
Medicine, offers abstracts of articles in scientifically based, peer-reviewed journals on complementary
and alternative medicine. Some abstracts link to the full text of articles.
The Cochrane Library
Web site: www.cochrane.org/reviews/clibintro.htm
The Cochrane Library is a collection of science-based reviews from the Cochrane Collaboration, an
international nonprofit organization that seeks to provide "up-to-date, accurate information about the
effects of health care." Its authors analyze the results of rigorous clinical trials (research studies in
people) on a given topic and prepare summaries called systematic reviews. Abstracts (brief
summaries) of these reviews can be read online without charge. You can search by treatment name
(such as the name of an herb) or medical condition. Subscriptions to the full text are offered at a fee and
are carried by some libraries.
NCCAM has provided this material for your information. It is not intended to substitute for the medical
expertise and advice of your primary health care provider. We encourage you to discuss any decisions
about treatment or care with your health care provider. The mention of any product, service, or therapy in
this information is not an endorsement by NCCAM.
This publication is not copyrighted and is in the public domain. Duplication is encouraged.
NCCAM Publication No. D190
Date Reviewed: August 2003
Editorial Changes Made: September 2004