The Ten Most Commonly Used Therapeutic Herbs

The Ten Most Commonly Used Therapeutic Herbs

Richard Sadovsky

Herbal therapies have become popular in the United States, with one in three Americans using some type of herbal remedy in the past year. A number of potential problems surround the use of these remedies. Patients are often unaware that about 25 percent of modern pharmaceuticals are derived from plants. Thus, the bioactivity of medicinal herbs is often underestimated. Patients who use herbal remedies often self-diagnose and may delay seeking medical attention. In addition, herbal remedies do not require evaluation and approval by the U.S. Food and Drug Administration, so information on side effects, drug interactions and product consistency is limited. Mar and Bent reviewed the literature on the 10 most commonly used herbs in the United States.

Their MEDLINE search was limited to English-language articles and human studies from 1966 to 1999. The most commonly used herbs are echinacea, St. John’s wort, ginkgo biloba, garlic, saw palmetto, ginseng, goldenseal, aloe, Siberian ginseng and valerian. Evidence for the use of each herb was reviewed, and statements regarding efficacy were based on findings presented in systematic reviews and randomized controlled studies. For a detailed summary of the evidence on each herb, see the accompanying table on page 1840.

The authors conclude that the more reliable products will include labeling that lists the botanical name, the milligram dose, the batch or lot number, the expiration date and the name and address of the manufacturer. Patients should be advised to avoid using a wide variety of herbs concomitantly because herb-herb interactions are poorly understood. The starting dosage should be the lowest at which the desired effects occur. Long-term use of herbal products should be discouraged because long-term effects are unknown. For more resources and information about herbal therapies, see the accompanying table on page 1838.


Mar C, Bent S. An evidence-based review of the

10 most commonly used herbs. WJM September 1999; 171:168-71.

On-Line Herbal Resources

American Botanical Council

U.S. Food and Drug Administration

Phytochemical database by James A. Duke

Herb Research Foundation

University of Washington Medicinal Herbal Garden

National Institute of Health

Office of Alternative Medicine

Adapted with permission from Mar C, Bent S. An evidence-based

review of the 10 most commonly used herbs. WJM 1999;171:168-71.

A Review of the Evidence for the Top 10 Therapeutic Herbs

Herb Common uses Dosage

Echinacea Treatment and prevention 300 to 400 mg dried

of upper respiratory extract three times daily

infections, common cold or 2 to 3 mL tincture

three times daily

St. John’s wort Mild to moderate 300 mg three times daily

depression of extract standardized

to 0.3% hypericin

Gingko biloba Dementia 40 mg three times daily

standardized to 6%

terpenoids and 24%


Garlic Hypertension, 600 to 900 mg per day,

hypercholesterolemia, standardized to 0.6% to

atherosclerosis 1.3% allicin

Saw palmetto Benign prostatic 320 mg four times daily

hyperplasia or 160 mg twice daily

Ginseng General health promotion, 200 to 300 mg per day of

sexual function, athletic extract standardized to

ability, energy, fertility [greater than] 7%

and others ginsenosides

Goldenseal Upper respiratory Not established

infections, common cold

Aloe Topical application for Topical dosages vary;

dermatitis, herpes, wound oral dosage is 20 to 30

healing and psoriasis; mg hydroxyanthracene

orally for constipation derivatives daily

Siberian ginseng Similar to ginseng 2 to 3 g of root daily

Valerian Insomnia, anxiety 400 mg at night

Herb Side effects and interactions Bottom line

Echinacea Rash, pruritis, dizziness, Inconclusive evidence

unclear long-term effects

on the immune system

St. John’s wort Gastrointestinal upset, Beneficial in mild to

photosensitivity moderate depression

Gingko biloba Mild gastrointestinal Beneficial in patients

distress, headache, possible with dementia

anticoagulant effects

Garlic Gastrointestinal upset, gas, Probable modest effect

reflux, nausea, allergic for decreasing lipids

reactions and antiplatelet and blood pressure


Saw palmetto Uncommon Probably beneficial

in benign prostatic


Ginseng High dosages may cause No conclusive evidence

diarrhea, hypertension, for any indication

insomnia, nervousness; may

interact with warfarin

Goldenseal Diarrhea, hypertension, No evidence for a

vasoconstriction beneficial effect

Aloe May delay wound healing after Inconclusive evidence

topical application; may

cause diarrhea and

hypokalemia with oral use

Siberian ginseng May alter digoxin levels No evidence for a

beneficial effect

Valerian Fatigue, tremor, headache, Inconclusive evidence

paradoxical insomnia; use

with sedative-hypnotic drugs

not advised

Adapted with permission from Mar C, Bent S. An evidence-based review of

the 10 most commonly used herbs. WJM 1999;171:168-71.

COPYRIGHT 2000 American Academy of Family Physicians

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