U.S. Food & Drug Administration
Tips For The Savvy Supplement User:
Making Informed Decisions And Evaluating Information
also available in Spanish)
FDA, as well as health professionals and their organizations, receive many
inquiries each year from consumers seeking health-related information, especially
about dietary supplements. Clearly, people choosing to supplement their diets
with herbals, vitamins, minerals, or other substances want to know more about
the products they choose so that they can make informed decisions about them.
The choice to use a dietary supplement can be a wise decision that provides health
benefits. However, under certain circumstances, these products may be unnecessary
for good health or they may even create unexpected risks.
Given the abundance and conflicting nature of information now available about
dietary supplements, you may need help to sort the reliable information from the
questionable. Below are tips and resources that we hope will help you be a savvy
dietary supplement user. The principles underlying these tips are similar to those
principles a savvy consumer would use for any product.
Note: Links to non-Federal government organizations found on this site are
provided solely as a service to consumers and do not represent an FDA endorsement
of these organizations or their products. (For resources see Selected
Do I need to think about my total diet?
Yes. Dietary supplements are intended to supplement the diets of some people,
but not to replace the balance of the variety of foods important to a healthy
diet. While you need enough nutrients, too much of some nutrients can cause problems.
You can find information on the functions and potential benefits of vitamins and
minerals, as well as upper safe limits for nutrients at the National Academy of
Sciences Web site at: http://www.iom.edu/iom/iomhome.nsf/Pages/FNB+Reports
Should I check with my doctor or healthcare provider
before using a supplement?
This is a good idea, especially for certain population groups. Dietary supplements
may not be risk-free under certain circumstances. If you are pregnant, nursing
a baby, or have a chronic medical condition, such as, diabetes, hypertension or
heart disease, be sure to consult your doctor or pharmacist before purchasing
or taking any supplement. While vitamin and mineral supplements are widely used
and generally considered safe for children, you may wish to check with your doctor
or pharmacist before giving these or any other dietary supplements to your child.
If you plan to use a dietary supplement in place of drugs or in combination with
any drug, tell your health care provider first. Many supplements contain active
ingredients that have strong biological effects and their safety is not always
assured in all users. If you have certain health conditions and take these products,
you may be placing yourself at risk.
- Some supplements may interact with prescription and over-the-counter medicines.
Taking a combination of supplements or using these products together with
medications (whether prescription or OTC drugs) could under certain circumstances
produce adverse effects, some of which could be life-threatening. Be alert to
advisories about these products, whether taken alone or in combination. For example:
Coumadin (a prescription medicine), ginkgo biloba (an herbal supplement), aspirin
(an OTC drug) and vitamin E (a vitamin supplement) can each thin the blood, and
taking any of these products together can increase the potential for internal
bleeding. Combining St. John's Wort with certain HIV drugs significantly reduces
their effectiveness. St. John's Wort may also reduce the effectiveness of prescription
drugs for heart disease, depression, seizures, certain cancers or oral contraceptives.
- Some supplements can have unwanted effects during surgery:
It is important to fully inform your doctor about the vitamins, minerals, herbals
or any other supplements you are taking, especially before elective surgery. You
may be asked to stop taking these products at least 2-3 weeks ahead of the procedure
to avoid potentially dangerous supplement/drug interactions -- such as changes
in heart rate, blood pressure and increased bleeding - that could adversely affect
the outcome of your surgery.
- Adverse effects from the use of dietary supplements should be reported
You, your health care provider, or anyone may report a serious adverse event or
illness directly to FDA if you believe it is related to the use of any dietary
supplement product, by calling FDA at 1-800-FDA-1088, by fax at 1-800-FDA-0178
or reporting on-line at: http://www.fda.gov/medwatch/how.htm.
FDA would like to know whenever you think a product caused you a serious problem,
even if you are not sure that the product was the cause, and even if you do not
visit a doctor or clinic. In addition to communicating with FDA on-line or by
phone, you may use the MedWatch form available from the FDA Web site.
Who is responsible for ensuring the safety and efficacy
of dietary supplements?
Under the law, manufacturers of dietary supplements are responsible for making
sure their products are safe before they go to market. They are also responsible
for determining that the claims on their labels are accurate and truthful. Dietary
supplement products are not reviewed by the government before they are marketed,
but FDA has the responsibility to take action against any unsafe dietary supplement
product that reaches the market. If FDA can prove that claims on marketed dietary
supplement products are false and misleading, the agency may take action also
against products with such claims.
Tips on Searching the Web for Information on Dietary Supplements
When searching on the Web, try using directory sites of respected organizations,
rather than doing blind searches with a search engine. Ask yourself the following
- Who operates the site?
Is the site run by the government, a university, or a reputable medical or health-related
association (e.g., American Medical Association, American Diabetes Association,
American Heart Association, National Institutes of Health, National Academies
of Science, or U.S. Food and Drug Administration)? Is the information written
or reviewed by qualified health professionals, experts in the field, academia,
government or the medical community?
- What is the purpose of the site?
Is the purpose of the site to objectively educate the public or just to sell a
product? Be aware of practitioners or organizations whose main interest is in
marketing products, either directly or through sites with which they are linked.
Commercial sites should clearly distinguish scientific information from advertisements.
Most nonprofit and government sites contain no advertising; and access to the site
and materials offered are usually free.
- What is the source of the information and does it have any
Has the study been reviewed by recognized scientific experts and published
in reputable peer-reviewed scientific journals, like the New England Journal of
Medicine? Does the information say "some studies show
" or does
it state where the study is listed so that you can check the authenticity of the
references? For example, can the study be found in the National Library of Medicine's
database of literature citations (PubMed link - http://www.ncbi.nlm.nih.gov/PubMed/
- Is the information current?
Check the date when the material was posted or updated. Often new research
or other findings are not reflected in old material, e.g., side effects or interactions
with other products or new evidence that might have changed earlier thinking.
Ideally, health and medical sites should be updated frequently.
- How reliable is the Internet or e-mail solicitations?
While the Internet is a rich source of health information,
it is also an easy vehicle for spreading myths, hoaxes and rumors about alleged
news, studies, products or findings. To avoid falling prey to such hoaxes, be
skeptical and watch out for overly emphatic language with UPPERCASE LETTERS and
lots of exclamation points!!!! Beware of such phrases such as: "This is not
a hoax" or "Send this to everyone you know."
- Ask yourself: Does it sound too good to be true?
Do the claims for the product seem exaggerated or unrealistic? Are there
simplistic conclusions being drawn from a complex study to sell a product? While
the Web can be a valuable source of accurate, reliable information, it also has
a wealth of misinformation that may not be obvious. Learn to distinguish hype
from evidence-based science. Nonsensical lingo can sound very convincing. Also,
be skeptical about anecdotal information from persons who have no formal training
in nutrition or botanicals, or from personal testimonials (e.g. from store employees,
friends, or online chat rooms and message boards) about incredible benefits or
results obtained from using a product. Question these people on their training
and knowledge in nutrition or medicine.
- Think twice about chasing the latest headline.
Sound health advice is generally based on a body of research, not a single study.
Be wary of results claiming a "quick fix" that depart from previous
research and scientific beliefs. Keep in mind science does not proceed by dramatic
breakthroughs, but by taking many small steps, slowly building towards a consensus.
Furthermore, news stories, about the latest scientific study, especially those
on TV or radio, are often too brief to include important details that may apply
to you or allow you to make an informed decision.
- Check your assumptions about the following:
- #1 Questionable Assumption
"Even if a product may not help me, it at least won't hurt me."
It's best not to assume that this will always be true. When consumed in high enough
amounts, for a long enough time, or in combination with certain other substances,
all chemicals can be toxic, including nutrients, plant components, and other biologically
- #2 Questionable Assumption
"When I see the term 'natural,' it means that a product is healthful and
safe." Consumers can be misled if they assume this term assures wholesomeness,
or that these food-like substances necessarily have milder effects, which makes
them safer to use than drugs. The term "natural" on labels is not well
defined and is sometimes used ambiguously to imply unsubstantiated benefits or
safety. For example, many weight-loss products claim to be "natural"
or "herbal" but this doesn't necessarily make them safe. Their ingredients
may interact with drugs or may be dangerous for people with certain medical conditions.
- #3 Questionable Assumption
" A product is safe when there is no cautionary information on the product
label." Dietary supplement manufacturers may not necessarily include
warnings about potential adverse effects on the labels of their products. If consumers
want to know about the safety of a specific dietary supplement, they should contact
the manufacturer of that brand directly. It is the manufacturer's responsibility
to determine that the supplement it produces or distributes is safe and that there
is substantiated evidence that the label claims are truthful and not misleading.
- #4 Questionable Assumption
" A recall of a harmful product guarantees that all such harmful products
will be immediately and completely removed from the marketplace." A product
recall of a dietary supplement is voluntary and while many manufacturers do their
best, a recall does not necessarily remove all harmful products from the marketplace.
- Contact the manufacturer for more information about
the specific product that you are purchasing.
If you cannot tell whether the product you are purchasing meets the same standards
as those used in the research studies you read about, check with the manufacturer
or distributor. Ask to speak to someone who can address your questions, some of
which may include:
- What information does the firm have to substantiate the claims made for the
product? Be aware that sometimes firms supply so-called "proof" of their
claims by citing undocumented reports from satisfied consumers, or "internal"
graphs and charts that could be mistaken for evidence-based research.
- Does the firm have information to share about tests it has conducted on the
safety or efficacy of the ingredients in the product?
- Does the firm have a quality control system in place to determine if the
product actually contains what is stated on the label and is free of contaminants?
- Has the firm received any adverse events reports from consumers using their
NOTE: You may obtain more information on how FDA regulates
dietary supplements and on the manufacturers' responsibilities for the products
they market at "Questions and Answers." http://www.cfsan.fda.gov/~dms/ds-faq.html
THE FOLLOWING ARE SELECTED REFERENCES THAT MAY HELP USERS UNDERSTAND AND
EVALUATE INFORMATION ENCOUNTERED ON THE INTERNET OR IN THE MARKETPLACE. (Links
to non-Federal government organizations found on this site are provided as a service
to our users and do not represent FDA endorsement of these organizations or their
materials. FDA cannot monitor other sites to ensure that the information is the
most current available.)
10 Things to Know About Evaluating Medical Resources on the Web
A short guide developed by the National Cancer Institute, NIH, to help you evaluate
medical Web sites. (July, 1999)
to Understand and Interpret Food and Health-Related Scientific Studies
This article provides an overview for understanding and interpreting food
and health-related scientific studies (from the International Food Information
Council, May 2000).
Sense of Health and Nutrition News
Provides tips for evaluating science.(IFIC, Food Insight. Jan/Feb 2001
Navigating the Internet
products and the Internet. A guide to finding reliable information.
This document provides advice from the World Health Organization to help internet
users obtain reliable, independent, and comparable information on the internet.
for Health: Finding Accurate Information on the Internet".
(IFIC Food Insight article, November-December, 2000)
Buying Medicines and Medical Products Online
This article provides tips and links for finding information on the web as well
as advice to help you determine the reliability of different web sites.
of Health Information.
Several links to other government and private sector web sites compiled by the
Department of Health and Human Services' Healthfinder web site to help you evaluate
online health information.
Product Claims and Labeling
"Claims That Can Be Made for Conventional Foods
and Dietary Supplements"
An FDA explanation of the various kinds of claims that can be made for foods and
supplements. (Updated April, 2001.)
"Staking a Claim to Good Health".
Reviews the health claims that FDA has authorized for use on food labels.
(FDA Consumer article, November December 1998.)
FDA Dietary Supplement Questions and Answers.
Provides information about what dietary supplements are, and how they are regulated,
including the labeling and claims that can be made for supplements.
Questions You Can Ask About Health Claims. "Improving
Public Understanding: Guidelines for Communicating Emerging Science on Nutrition,
Food Safety and Health."
These questions were developed to help journalists and scientists accurately convey
health information. You can ask yourself these questions to help judge whether
the information you are reading is fairly presented (the International Food Information
Health Claims: Add a Dose of Skepticism
This FDA/FTC joint agency information piece focuses on how to assess claims and seek advice,
and avoid becoming a victim of health fraud. The information discusses how to
minimize being cheated out of money, time, and health. (September 2001)
The Story of the Laws Behind the Labels.
This article on the history of food and drug laws provides useful insights
on the regulation of health claims over the years. (FDA Consumer, June
Advertising Dietary Supplements
Supplements: An Advertising Guide for Industry".
This document describes the factors that FTC takes into account in deciding whether
an ad is truthful and not misleading. You can use them to judge the advertisements
Dietary Supplements and Kids
for Kids' Dietary Supplements Leaves Sour Taste"
( FTC article, May 2000.)
FDA Safety Information and Adverse Event Reporting Program.
The Food and
The Food and Nutrition Board (FNB), National Academy of Sciences, as part of its
mission, establishes principles and guidelines of adequate dietary intake. The
FNB issues reports such as "Dietary Reference Intakes: Thiamin, Riboflavin,
Niacin, Vitamin B6, Folate, Vitamin B12, Pantothenic Acid, Biotin, and Choline."
NUTRITION.GOV, a new federal resource, provides easy access to all online federal
government information on nutrition, including dietary supplements.
Plus Health Information: Vitamin and Mineral Supplements
MEDLINE Plus Health Information is a service of the National Library of Medicine,
National Institutes of Health, that provides information on health topics, including
vitamin and mineral supplements..
Information on Dietary Supplements (IBIDS)
The International Bibliographic Information on Dietary Supplements (IBIDS) NIH,
Office of Dietary Supplements is a database of published, international, scientific
literature on dietary supplements, including vitamins, minerals, and botanicals.
National Center for Complementary and Alternative
Medicine, NIH .
The National Center for Complementary and Alternative Medicine (NCCAM) at the
National Institutes of Health (NIH, www.nih.gov)
is dedicated to exploring complementary and alternative healing practices in the
context of rigorous science; training CAM researchers; and disseminating authoritative
This document was issued in January 2002.
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Hypertext updated by kwg/las/cjm 2005-MAR-17