How do you know if herbal supplements' claims are true?

Manufacturers of herbal supplements are responsible for ensuring that the claims they make about their products aren't false or misleading and that they're backed up by adequate evidence. However, they aren't required to submit this evidence to the FDA.

So be a smart consumer and do a little homework. Don't just rely on a product's marketing. Look for objective, research-based information to evaluate a product's claims. To get reliable information about a particular supplement:

  • Ask your doctor or pharmacist. Even if they don't know about a specific supplement, they may be able to point you to the latest medical guidance about its uses and risks.
  • Look for scientific research findings. Two good sources include the National Center for Complementary and Alternative Medicine (NCCAM) and the Office of Dietary Supplements. Both have websites that provide information to help consumers make informed choices about dietary supplements.
  • Contact the manufacturer. If you have questions about a specific product, call the manufacturer or distributor. Ask to talk with someone who can answer questions, such as what data the company has to substantiate its products' claims.

Who shouldn't use herbal supplements?

If you have health issues, it's essential that you talk with your doctor before trying herbal supplements. In fact, in some high-risk situations, your doctor will likely recommend that you avoid herbal supplements altogether.

It's especially important that you talk to your doctor before using herbal supplements if:

  • You're taking prescription or over-the-counter (OTC) medications. Some herbs can cause serious side effects when mixed with prescription and OTC drugs, such as aspirin, blood thinners or blood pressure medications. Talk to your doctor about possible interactions.
  • You're pregnant or breast-feeding. Medications that may be safe for you as an adult may be harmful to your fetus or your breast-feeding infant. As a general rule, don't take any medications — prescription, OTC or herbal — when you're pregnant or breast-feeding unless your doctor approves.
  • You're having surgery. Many herbal supplements can affect the success of surgery. Some may decrease the effectiveness of anesthetics or cause dangerous complications, such as bleeding or high blood pressure. Tell your doctor about any herbs you're taking or considering taking as soon as you know you need surgery.
  • You're younger than 18 or older than 65. Older adults may metabolize medications differently. And few herbal supplements have been tested on children or have established safe doses for children.

Safety tips for using herbal supplements

If you've done your homework and plan to try an herbal supplement, play it safe with these tips:

  • Follow supplement instructions. Don't exceed recommended dosages or take the herb for longer than recommended.
  • Keep track of what you take. Take only one supplement at a time to determine if it's effective. Make a note of what you take — and how much for how long — and how it affects you.
  • Be cautious about supplements manufactured outside the United States. Herbal products from some European countries are highly regulated and standardized. But toxic ingredients and prescription drugs have been found in supplements manufactured elsewhere, particularly China, India and Mexico.
  • Check alerts and advisories. The FDA and NCCAM maintain lists of supplements that are under regulatory review or that have been reported to cause adverse effects. Check their websites periodically for updates.
Nov. 17, 2011 See more In-depth