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JAMA Patient Page
March 8, 2016

Herbal Medications

JAMA. 2016;315(10):1068. doi:10.1001/jama.2015.19388

Herbal medications are commonly used in both adults and children.

There are numerous concerns related to the use of herbal medicines because unlike conventional medications, they are not regulated by the US Food and Drug Administration and manufacturers do not have to prove the safety and efficacy of herbal medications before they are made available to the public.

Are Herbal Medications Beneficial?

Herbal medications are rarely tested by high-quality research, and clear proof of beneficial effects is often lacking. Only the use of cranberry for prevention of recurrent urinary tract infections in women is supported by some scientific evidence. The efficacy of other commonly used herbal medications has not been proven. For instance, the beneficial effect of St John’s wort for short-term treatment of mild to moderate depression is still debated. Use of Echinacea for treatment of colds is not supported by scientific data. Similarly, there is questionable evidence on the efficacy of ginseng, which is often used to improve physical and cognitive performance. Ginkgo biloba has been marketed to improve memory and cognitive performance, but there is no consistent scientific evidence to support this use. The efficacy of garlic in lowering cholesterol levels, treating hypertension, and reducing cardiovascular risk is uncertain. Furthermore, no beneficial effect has been attributed to ginger for treatment of nausea or to soy for control of menopausal symptoms.

Possible Negative Effects of Herbal Medications

Herbal medications can mistakenly be perceived as safe because they are natural products. They may produce negative effects such as allergic reactions, rashes, asthma, headaches, dizziness, agitation, dry mouth, seizures, fatigue, tachycardia, nausea, vomiting, and diarrhea. Severe side effects have also been reported. Cases of hepatotoxicity (liver damage) were reported for kava kava and life-threatening anaphylactic reactions have been reported for most herbal medications. Herbal medications may also modify the effect of conventional medications. For example, cranberry and Ginkgo biloba should be used cautiously by people who take blood-thinning medications (such as warfarin or aspirin) because of an increased risk of bleeding. St John’s wort interferes with the effect of many medications, including birth control pills, antidepressants, and anti-HIV medications. Also, the active ingredients of many herbal medications are not readily known, and contamination has been reported.

What Should Be Done Before Starting an Herbal Medication?

  • Discuss with your doctor the possible harmful effects of herbal medications and whether they interact with other medications you are using or with any diseases you have. Particularly if you are an older adult, elimination of herbal medications from your body might be reduced, leading to a higher risk of harmful effects.

  • Always consider new symptoms as a potential effect of herbal medications. If you experience a new symptom, stop the medication, report the side effect to your doctor, and consider reporting it through the Safety Reporting Portal (www.safetyreporting.hhs.gov).

  • Avoid use of herbal medications in children and if you are pregnant, attempting to become pregnant, or breastfeeding. Herbal medications have not been tested in pregnant women or in children.

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Article Information

Conflict of Interest Disclosures: All authors have completed and submitted the ICMJE Form for Disclosure of Potential Conflicts of Interest and none were reported.

Source: National Center for Complementary and Integrative Health

Topic: Complementary and Alternative Medicine