Herbal supplements: What to know before you buy

Regulations ensure that herbal supplements meet manufacturing standards but don't guarantee that they're safe or effective. Do your homework 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, are one type of dietary supplement available for purchase. Herbal supplements aren't new — plants have been used for medicinal purposes for thousands of years.

But herbal supplements generally 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 medication-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 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 selling dietary supplements.
  • 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.
  • Companies aren't allowed to make a specific medical claim. An example of a specific medical claim might be, "This herb reduces the frequency of urination due to an enlarged prostate."
  • 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 out of supplements, as well as make sure that the right ingredients are included in appropriate amounts.
  • The FDA is responsible for monitoring dietary supplements that are on the market. 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
  • The FDA can intervene to remove dangerous products from the market

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

These 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 prescribed medications could lead to harmful, even life-threatening results.

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 labels of all herbal supplements include this information:

  • The name of the herbal supplement
  • The name and address of the 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 a supplement's label, ask your doctor or pharmacist for an explanation.

An easy way to compare ingredients in products is to use 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. 08, 2017 See more In-depth