Shelves of supplement bottles

Dietary Supplements

Be a Savvy Consumer and Protect Yourself from Health Fraud


A few dietary supplements are clearly beneficial to health. For example:

  • Folic acid can help pregnant women reduce the risk of having a child with birth defects;
  • A mix of nutrients (vitamins C and E, zinc, copper, and lutein) can slow vision loss in people with macular degeneration; 
  • Calcium and iron can help people who don’t get enough of those nutrients from food;
  • Vitamin D can help people who don't get enough sunlight living in northern latitudes during the winter or those with vitamin D deficiency;
  • Vitamin B-12 can help older people who cannot digest and absorb the B-12 in foods very well.

But these and other medically supported uses of supplements are the exceptions. When it comes to the dietary supplement marketplace, misinformation, exaggeration, deception, and even scams abound.  Our Consumer’s Guide, below, can help you identify dubious claims, understand the potential health risks in taking supplements, and use resources with credible and accurate information. On this page, you will find information on:

Please remember, taking dietary supplements can impact your health and other medical treatments. The information on this page is for informational purposes only. Each dietary supplement can impact each person differently, and you should always consult a medical professional before taking a dietary supplement.

Be aware of the risks of taking supplements.

The federal law that governs oversight of supplements is riddled with loopholes, and important rules are rarely enforced. Many consumers assume that, like prescription drugs, all supplements must be proven safe and effective before being sold to the public. Unfortunately, this is generally not the case.

Investigations by the Center for Science in the Public Interest find that claims that dietary supplement manufacturers make about the benefits of their products are frequently misleading or unsubstantiated. In addition:

  • Hundreds of weight-loss, workout, and sexual enhancement supplements also have been found by federal regulators to be tainted with unlabeled stimulants or illegal, dangerous drugs;
  • Supplements can have potentially harmful interactions with certain prescription drugs or medical conditions.
  • Other supplements may contain allergens that are not declared on the labels;
  • And some supplements, especially herbal products, do not contain exactly what’s on the label. The adulteration of herbal supplements with fillers and synthetic chemicals intended to fool quality-control testing is rampant worldwide and has persisted as a problem for years. 

For example, St. John’s Wort, a supplement that is believed by some to treat depression, menopausal symptoms, and smoking addiction (among other ailments) interacts with critical prescription medications, including blood thinners, anti-retroviral medications for HIV/AIDS, antidepressants, birth-control pills, some cancer medications, and other necessary medications. In addition, the drug is prone to other side effects such as increased sensitivity to sunlight, anxiety, dizziness, gastrointestinal symptoms, and sexual dysfunction.

Other supplements, including those that are commonly consumed, have also been associated with a range of serious and problematic health conditions, such as gingko biloba and saw palmetto.

Beware of claims and business practices intended to mislead you.

According to the Federal Trade Commission (FTC), here are some examples of common claims and business practices in the dietary supplement market that you should watch out for:

  • “Natural” or “non-toxic:” Such claims do not mean that a supplement has no side effects or is safe to use. 
  • “Treat,” “prevent,” or “cure” claims: Avoid any supplement that claims to treat, prevent, or cure diseases like cancer, dementia, depression, and diabetes, or conditions like ADHD or drug addiction. Claims like these are unproven, illegal and make a supplement an unapproved drug by law.
  • “Supports,” “maintains,” or “enhances” claims: Supplements can make these kids of fuzzy claims with very little evidence. Be skeptical..
  • Testimonials: Unfortunately, fake online reviews of products are now common.  
  • Claims suggesting proven effectiveness without citing a credible source: These include phrases like “scientific breakthrough,” “clinically proven,” “miraculous cure,” “secret ingredient,” or “ancient remedy.” Ignore them. Be aware that some labels or websites cite poor-quality studies that were funded or conducted by the company.
  • “Cure-all” claims for a wide variety of ailments: If something sounds too good to be true, it usually is.
  • “Patented:” Patents are awarded to ideas that are novel, non-obvious, and potentially useful, but that is no guarantee that they actually work.
  • “Free trial:”. This most likely means free only if you can quickly cancel the sale, sometimes before you have time to evaluate the product. Otherwise, the supplement manufacturer may start charging your credit card hefty monthly fees.
  • “Money-back” guarantee: The fine print in the “guarantee” may make it impossible to get your money back.
  • Risky websites: Avoid websites that fail to list the company’s name, street address, phone number, or other contact information. They often have something to hide and you’ll have no way to contact them if your purchase never arrives.

Additional CSPI resources and advocacy on dietary supplements

Nutrition Action Healthletter articles on dietary supplements

CSPI’s Nutrition Action Healthletter also offers clear, research-based information on supplements.  Below is a selection of past coverage of the issue from Nutrition Action.  

To get up-to-date information on supplements and for more articles on nutrition, subscribe to Nutrition Action today.

Additional Public Resources

Unsure about certain supplements? Try these additional public resources:

  • Your healthcare provider: Your primary care physician, physician’s assistant, nurse practitioner, or pharmacist may be able to discuss your health needs and the benefits and risks of taking supplements. They may also be able to make sure that a dietary supplement doesn’t interact with your medications.
  • National Institutes of Health (NIH): Free fact sheets, prepared by expert scientists, cover many of the most popular dietary supplements and include information about the proven benefits, if any, the proper dosages, and potential adverse effects from using the supplements.
  • FDA Consumer Updates: A few times a year, FDA publishes a “Consumer Update” cautioning consumers about an unsafe or fraudulent category of supplements.

Reporting supplement issues to the FDA

If you or someone you know may have suffered a bad reaction or adverse event from taking a dietary supplement:

Tell the Food and Drug Administration. The FDA’s Adverse Event Reporting System (CAERS) allows consumers, health professionals, manufacturers, researchers, and public health officials to report safety concerns about dietary supplements. You can file a report on FDA’s Safety Reporting Portal (SRP)