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 18 or older than 65. Few herbal supplements have been tested in children or have established safe doses for children. And older adults may metabolize medications differently.
How do you know what’s in herbal supplements?
The FDA requires that supplement labels include this information:
- Name of the supplement
- Name and address of the manufacturer or distributor
- Complete list of ingredients
- Serving size, amount and active ingredient
If you don’t understand something on the label, ask your doctor or pharmacist to explain.
An easy way to compare ingredients in products is to use the Dietary Supplement Label Database, which is available on the website for the U.S. National Institute of Health. You can look up products by brand name, use, active ingredient or manufacturer.
How do you know if supplement 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. But they aren’t required to submit this evidence to the FDA.
So be a smart consumer. 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 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 in the U.S. are the National Center for Complementary and Integrative Health, and the Office of Dietary Supplements. Both have websites 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 product claims.
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 instructions. Don’t exceed recommended dosages or take for longer than recommended.
- Keep track of what you take. Make a note of what you take — and how much for how long — and how it affects you. Stop taking the supplement if it isn’t effective or doesn’t meet your goals for taking it.
- Choose your brand wisely. Stick to brands that have been tested by independent sources, such as ConsumerLab.com, U.S. Pharmacopeia and NSF International.
- Check alerts and advisories. The FDA maintains a list of supplements that are under regulatory review or that have been reported to cause adverse effects. Check the FDA website periodically for updates.
- Dietary supplements: What you need to know. Office of Dietary Supplements. https://ods.od.nih.gov/pubs/DS_WhatYouNeedToKnow.pdf. Accessed Dec. 28, 2020.
- Using dietary supplements wisely. National Center for Complementary and Integrative Health. https://nccih.nih.gov/health/using-dietary-supplements-wisely/. Accessed Dec. 28, 2020.
- AskMayoExpert. Integrative medicine (complementary and alternative medicine). Mayo Clinic, 2019.
- Saper RB. Overview of herbal medicine and dietary supplements. https://www.uptodate.com/contents/search. Accessed Dec. 28, 2020.
- Dietary Supplement Label Database (DSLB). Office of Dietary Supplements. https://ods.od.nih.gov/Research/Dietary_Supplement_Label_Database.aspx. Accessed Dec. 28, 2020.
- Tips for dietary supplement users. U.S. Food & Drug Administration. https://www.fda.gov/food/information-consumers-using-dietary-supplements/tips-dietary-supplement-users. Accessed Dec. 28, 2020.
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