Herbal Supplements May Not be as Safe as They Sound

Yvette C. Terrie

Herbal supplements, sometimes referred to as "botanicals," have been used for medicinal purposes for many centuries, and they continue to gain popularity among consumers today. These supplements are marketed for the prevention and management of many disease states and ailments. Currently, an estimated 75 percent of the world's population have used or are using some type of herbal supplement.

In the United States, an estimated one in five adults has used at least one natural product in the past year. Examples of some of the most common herbal supplements sold in this country include echinacea, flaxseed, ginseng, ginkgo, saw palmetto, St John's wort, black cohosh, evening primrose, milk thistle and garlic.

As the popularity of these supplements continues to increase, some people elect to use them in place of traditional medications. There are several factors to consider prior to using these natural supplements. While these are considered to be natural supplements, they may still cause several types of drug/supplement interactions and serious adverse effects, as well as exacerbate certain medical conditions.

Are Herbal Supplements Safe?

The Food and Drug Administration regulates herbs and other dietary supplements differently from traditional medications. The standards of safety and efficacy that traditional medications have to meet before gaining approval to be marketed do not apply to these types of supplements. The Dietary Supplement Health and Education Act has exempted manufacturers of herbal supplements from these regulations.

Before Using a Herbal Supplement

If you are considering using an herbal supplement, you should be aware that many herbal supplements may interact with both prescription and nonprescription medications and can cause some very serious interactions and adverse effects. For example, the herbal supplement St. John's wort is known to interact with numerous medications such as antidepressants, blood thinners, allergy medications, drugs that suppress the immune system, birth control pills and cardiovascular drugs like digoxin. The herbal supplements feverfew, ginger and ginkgo can interact with some drugs used for breast cancer and a host of other medications. See more examples below. (The prescription medicine is listed first, with examples of interacting herbal supplements listed beside it.)

--Anticoagulants, nonsteroidal anti-inflammatory drugs, antiplatelet agents: garlic, ginkgo, St. John's wort, ginseng, saw palmetto, ginger, cranberry

--Hypoglycemic agents: garlic, ginkgo, ginseng, cranberry

--Anticonvulsants: ginkgo, St. John's wort, valerian

-- Digoxin: St. John's wort, ginseng, ginger

--Antiviral medications for HIV infection: garlic, St. John's wort, ginseng, cranberry

--Oral contraceptives: St. John's wort, kava

--Chemotherapy: St. John's wort, ginseng, kava, cranberry

Below is a list of herbal supplements along with their possible side effects:

--Echinacea: fatigue, dizziness, headache and gastrointestinal symptoms

--Garlic: nausea, burning sensation in mouth, throat and stomach, halitosis and body odor

--Ginkgo biloba: nausea, dyspepsia, headache and heart palpitations

--Saw palmetto: headache and diarrhea

--Ginseng: anorexia, rash, changes in blood pressure and headache

--St. John's Wort: photosensitivity, dry mouth, dizziness and confusion

--Bilberry: No adverse effects reported in literature

If you have allergies, especially allergies to plants, weeds or pollen, you should consult your primary health care provider before taking herbal supplements. Patients taking blood thinners should also always consult their primary health care provider before using any of these supplements. Since older individuals may have a greater incidence of having multiple medical conditions and are more likely to take multiple medications, it is imperative that they also consult with their primary health care provider before using any herbal supplements to avoid any possible interactions or contraindications.

Always talk to your doctor before taking an herbal supplement if you have any of the following health problems:

Blood clotting disorders



--An enlarged prostate gland



--Heart disease


--Immune system disorders

--Thyroid problems

--Parkinson's disease

--History of liver or kidney problems

--History of stroke

Make sure you discuss the issue of using herbal supplements with your primary health care provider to help you make a safe choice. Remember, "natural" doesn't always mean safe and free of adverse effects. When it comes to your health, always ask questions when in doubt.


For more information on herbal supplements, visit the National Institutes of Health's Center for Alternative and Complementary Medicine website.

The National Institutes of Health Medline Plus website lists many of the most common herbal supplements and information about their uses, dosages, adverse effects and drug interactions.

If you experience an adverse reaction to an herbal supplement, you may report the possible reaction to the Food and Drug Administration at www.FDA.gov/medwatch or contact them at 1-800- FDA-1088.

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Note: This article was originally published on March 19, 2012, on PharmacyTimes.com. It has been edited and republished by U.S. News.