Dietary supplement advertising and promotion

Keep in mind that a great deal of what you hear or read about dietary supplements is based on anecdotal evidence. Anecdotal evidence is based on people’s (even doctors’) personal experiences or opinions rather than objective, controlled research studies.

Be skeptical of sources that make grand claims based on a few people’s testimonials or vague references to “scientific proof.” The rule “if it sounds too good to be true, it probably is” usually applies to such claims. Keep in mind that the makers and sellers of supplements have a financial interest in promoting their products.

Supplement makers do not have to get FDA (US Food and Drug Administration) approval to market their products. The FDA does look at potentially illegal products (that is, products that may be unsafe or make false or misleading claims). But they can only do this after the product is on the market. As its resources permit, the FDA also looks at supplement labels and other information, such as package inserts, claims, and Internet ads. But it cannot review all of the many products on the market today.

No matter what they claim, dietary supplements are not intended to treat, diagnose, cure, or relieve the effects of diseases. They cannot completely prevent diseases, as some vaccines can. But some supplements are useful in reducing the risk of certain diseases. They are allowed to make label claims about these uses. For example, folic acid supplements may make a claim about reducing the risk of birth defects of the brain and spinal cord when taken by pregnant women.

If a supplement claims to do the same thing as a prescription drug, you are right to be doubtful. The claim may be false, or the product may contain an illegal drug. (See “What kinds of problems have there been with supplements and herbs?” in “FDA regulation of drugs versus dietary supplements.”)

Look past the advertising for evidence or research on the supplement from objective, third-party sources. See Complementary and Alternative Methods and Cancer to learn how to do this. 

The American Cancer Society medical and editorial content team

Our team is made up of doctors and oncology certified nurses with deep knowledge of cancer care as well as journalists, editors, and translators with extensive experience in medical writing.

Last Revised: March 31, 2015

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