Herbal supplements: What to know before you buy

Regulations ensure that herbal supplements meet manufacturing standards but aren’t a guarantee of effectiveness. Do your homework before you buy.

By Mayo Clinic Staff

Echinacea to prevent colds. Ginkgo to improve memory. Herbal remedies aren’t new — plants have been used for medicinal purposes for thousands of years.

But herbal supplements generally haven’t received the same scientific scrutiny and aren’t as strictly regulated as medications. Yet herbs and herbal products — including those labeled as “natural” — can have strong effects in the body.

It’s important to learn about potential benefits and side effects of herbal supplements before you buy. Be sure to talk with your doctor, especially if you take any medicines, have a chronic health problem, or are pregnant or breastfeeding.

Are herbal supplements regulated?

Herbal supplements are regulated by the U.S. Food and Drug Administration (FDA), but not as strictly as prescription or over-the-counter (OTC) drugs. They fall under a category called dietary supplements.

Dietary supplement makers don’t need FDA approval to sell their products, but they must:

  • Ensure that their supplements are free of contaminants and that they’re accurately labeled.
  • Have research to support claims that a product addresses a nutrient deficiency or supports health, and include a disclaimer that the FDA hasn’t evaluated the claim.
  • Avoid making specific medical claims. For example, a company can’t say: “This herb reduces the frequency of urination due to an enlarged prostate.” The FDA can take action against companies that make false or unsupported claims to sell their supplements.

These regulations provide assurance that:

  • Herbal supplements meet certain quality standards
  • The FDA can remove dangerous products from the market

However, the rules don’t guarantee that herbal supplements are safe for anyone to use.

Who shouldn’t use herbal supplements?

Herbal products can pose unexpected risks because many supplements contain active ingredients that have strong effects in the body. For example, taking a combination of herbal supplements or using supplements together with prescription drugs could lead to harmful, even life-threatening results.

It’s especially important to talk with your doctor about herbal supplements if:

  • You’re taking prescription or OTC medications. Some herbs can cause serious side effects when mixed with medications such as aspirin, blood thinners and blood pressure medications.
  • You’re pregnant or breastfeeding. Medications that may be safe for you as an adult may be harmful to your baby.
  • You’re having surgery. Many herbal supplements can affect the success of surgery. Some may decrease the effectiveness of anesthesia or cause dangerous complications, such as bleeding.
  • You’re younger than