Herbal supplements: What to know before you buy

Herbal supplements aren't right for everyone. Get the facts before you buy.

By Mayo Clinic Staff

Echinacea to prevent colds. Ginkgo to improve memory. Flaxseed to lower cholesterol. The list of herbal remedies goes on and on.

Herbal supplements, sometimes called botanicals, aren't new. Plants have been used for medicinal purposes for thousands of years. However, herbal supplements haven't been subjected to the same scientific scrutiny and aren't as strictly regulated as medications. For example, although makers of herbal supplements must follow good manufacturing practices — to ensure that supplements are processed consistently and meet quality standards — they don't have to get approval from the Food and Drug Administration (FDA) before putting their products on the market.

Yet all herbs — including herbal supplement products labeled as "natural" — can have drug-like effects. Anything strong enough to produce a positive effect, such as lowered cholesterol or improved mood, is also strong enough to carry risk. So it's important to do your homework and investigate potential benefits and side effects of herbal supplements before you buy. And be sure to talk with your doctor, especially if you take medications, have chronic health problems, or are pregnant or breast-feeding.

Are herbal supplements safe?

Herbal supplements are regulated by the FDA, but not as drugs or as foods. They fall under a category called dietary supplements. The rules for dietary supplements are as follows:

  • Manufacturers don't have to seek FDA approval before putting dietary supplements on the market. In addition, companies can claim that products address a nutrient deficiency, support health or are linked to body functions — if they have supporting research and they include a disclaimer that the FDA hasn't evaluated the claim.
  • Manufacturers must follow good manufacturing practices to ensure that supplements are processed consistently and meet quality standards. These regulations are intended to keep the wrong ingredients and contaminants, such as pesticides and lead, out of supplements, as well as make sure that the right ingredients are included in appropriate amounts.
  • Once a dietary supplement is on the market, the FDA is responsible for monitoring its safety. If the FDA finds a product to be unsafe, it can take action against the manufacturer or distributor or both, and may issue a warning or require that the product be removed from the market.

These regulations provide assurance that herbal supplements meet certain quality standards and that the FDA can intervene to remove dangerous products from the market.

The rules do not, however, guarantee that herbal supplements are safe for anyone to use. Because many supplements contain active ingredients that have strong effects in the body, these products can pose unexpected risks. For example, taking a combination of herbal supplements or using supplements together with prescribed medications could lead to harmful, even life-threatening results. For this reason, it's important to talk with your doctor before using herbal supplements.

How do you know what's in herbal supplements?

The FDA requires that the following information be included on the labels of all herbal supplements:

  • The name of the herbal supplement
  • The name and address of manufacturer or distributor
  • A complete list of ingredients — either in the Supplement Facts panel or listed beneath it
  • Serving size, amount and active ingredient

If you don't understand something on an herbal supplement's label, ask your doctor or pharmacist for an explanation.

An easy way to compare ingredients in products is by using the Dietary Supplement Label Database, which is available on the National Institute of Health's website. The database has information on the ingredients for thousands of dietary supplements sold in the United States. You can look up products by brand name, uses, active ingredient or manufacturer.

Nov. 14, 2014 See more In-depth