Goldenseal (Hydrastis canadensis) is one of the most popular herbs in the United States, often combined with echinacea and sold to treat or prevent colds. But there is no evidence that it works. In fact, there is very little scientific evidence that goldenseal works to treat any condition.

Nevertheless, goldenseal is often said to kill bacteria and is sometimes used to treat eye infections, diarrhea, urinary tract infections, canker sores, and vaginitis. A substance in goldenseal, called berberine, does kill some kinds of bacteria and fungus in test tube studies. But scientists do not know if goldenseal would kill any germs in people.

Goldenseal is also popular because of a rumor that taking the herb can help block a positive test for illegal drugs. There is no evidence that it works, and several studies have reported that taking goldenseal does not change the results of a drug test.

Goldenseal is a small plant with a single hairy stem. It has two jagged 5 lobed leaves, small flowers, and raspberry-like fruit. The bitter tasting rhizome, or root, is bright yellow or brown, twisted, and wrinkled. Goldenseal can be found growing wild in rich, shady soil in the northern United States, but it is now grown mostly on farms.

Goldenseal contains a compound called berberine that kills many types of bacteria in test tubes, including the ones that cause diarrhea. Berberine also kills a wide range of other types of germs in test tubes, such as those that cause candida (yeast) infections and parasites such as tapeworms and Giardia. Berberine may also activate white blood cells, making them better at fighting infection and strengthening the immune system.

Berberine is sometimes used as an antibiotic, although studies have not shown whether it works or not in people. It has been studied to treat H. pylori infection (the bacterium that causes ulcers) and infectious diarrhea. It is sometimes recommended to treat urinary tract infections (UTIs). Berberine may also be useful in heart failure. However, some experts think the berberine in goldenseal is not absorbed very well when it is taken by mouth.

ANTIBIOTIC OR IMMUNE BOOSTER

Today, goldenseal is sold to help with digestion, soothe an upset stomach, and to kill bacteria. It is considered a natural antibiotic and is often combined with echinacea and promoted as strengthening the immune system. However, only one study found that goldenseal might help boost white blood cells (a measure of the infection-fighting ability of the immune system), and the study was not well designed.

UPPER RESPIRATORY PROBLEMS

Goldenseal is often found in herbal remedies for hay fever (allergic rhinitis), colds, and the flu. There is no real evidence that it works to treat upper respiratory infections or allergies in humans, however. It may help ease a sore throat, which often accompanies cold or flu.

MINOR WOUNDS

Because goldenseal seems to have antiseptic properties in test tubes, it is sometimes used to disinfect cuts and scrapes.

OTHER USES

It is commonly used to treat several skin, eye, and mucous membrane problems, such as sinusitis, pink eye, and urinary tract infections. It is also available in mouthwashes for sore throats and canker sores.

Not many scientific studies have looked at goldenseal. Some have looked at berberine, one of the active compounds in goldenseal. Berberine is widely used in Traditional Chinese Medicine (TCM) to treat dysentery and infectious diarrhea. Berberine may work in humans to treat malaria, heart failure, and some types of infections, including upper respiratory problems. It may also dilate blood vessels and help treat heart failure. However, oral goldenseal has only very small amounts of berberine, so it is impossible to say whether or not goldenseal would work to treat these conditions.

Goldenseal is available in tablets and capsules (containing the powdered root), liquid extracts, and glycerites (low alcohol extracts). Goldenseal is often combined with echinacea.

Goldenseal is not recommended for children unless your doctor says so. Never give goldenseal to an infant.

For adult use, goldenseal can be taken by mouth. It is often mixed with water and other liquids to create different skin washes, mouthwash, and even as a vaginal douche. Ask your health care provider to find the right kind and dose for you.

The use of herbs is a time-honored approach to strengthening the body and treating disease. Herbs, however, contain components that can trigger side effects and interact with other herbs, supplements, or medications. For these reasons, you should take herbs with care, under the supervision of a health care provider qualified in the field of botanical medicine.

Pregnant or breastfeeding women should not use goldenseal.

People with high blood pressure, liver disease, or heart disease should ask their provider before taking goldenseal.

Goldenseal can irritate the skin, mouth, throat, and vagina. It may also cause an increased sensitivity to sunlight.

Goldenseal may interfere with some medications. If you are taking prescription or over-the-counter medications, ask your doctor before taking goldenseal.

It is possible that berberine (a major component of goldenseal) and goldenseal itself may interact with many medications, including some that are broken down by the liver and some that are affected by a cell protein. For that reason, anyone who takes any prescription or over-the-counter medication should check with their doctor before taking goldenseal.

Cyclosporine: Goldenseal may cause levels of cyclosporine in the body to get too high.

Digoxin: Goldenseal may raise blood levels of digoxin, a medication used to treat heart conditions. This can increase the risk of side effects.

Tetracycline: One study reported that berberine may cause tetracycline antibiotics to not work as well.

Anticoagulants (blood thinners): Theoretically, goldenseal and berberine could increase the risk of bleeding, especially if you take blood thinners. Some blood thinners include:

• Warfarin (Coumadin)
• Plavix (Clopidogrel)
• Aspirin

Other drugs: Goldenseal may interact with many medications, including:

• Some chemotherapy drugs
• Some drugs to treat HIV
• Amitriptyline (Elavil)
• Cimetidine (Tagamet)
• Cisapride (Propulsid)
• Clarithromycin (Biaxin)
• Diltiazem (Cardizem)
• Donepezil (Aricept)
• Erythromycin
• Fexofenadine (Allegra)
• Fluoxetine (Prozac)
• Indinavir (Crixivan)
• Loperamide (Imodium)
• Lovastatin (Mevacor)
• Metoprolol (Lopressor, Toprol XL)
• Olanzapine (Zyprexa)
• Ranitidine (Zantac)
• Sildenafil (Viagra)
• Tramadol (Ultram)
• Trazodone (Desyrel)
• Triazolam (Halcion)

Abidi P, Chen W, Kraemer FB, et al. The medicinal plant goldenseal is a natural LDL-lowering agent with multiple bioactive components and new action mechanisms. J Lipid Res. 2006;47(10):2134-47.

Ang ES, Lee ST, Gan CS, et al. Evaluating the role of alternative therapy in burn wound management: randomized trial comparing moist exposed burn ointment with conventional methods in the management of patients with second-degree burns. Med Gen Med. 2001;3:3.

Cech NB, Junio HA, Ackermann LW, Kavanaugh JS, Horswill AR. Quorum quenching and antimicrobial activity of goldenseal (Hydrastis canadensis) against methicillin-resistant Staphylococcus aureus (MRSA). Planta Med. 2012 Sep;78(14):1556-61.

Chen S, Wan L, Couch L, et al. Mechanism study of goldenseal-associated DNA damage. Toxicol Lett. 2013;221(1):64-72.

Clement-Kruzel S, Hwang SA, Kruzel MC, Dasgupta A, Actor JK. Immune modulation of macrophage pro-inflammatory response by goldenseal and Astragalus extracts. J Med Food. 2008 Sep;11(3):493-8.

Hwang BY, Roberts SK, Chadwick LR, et al. Antimicrobial constituents from goldenseal (the Rhizomes of Hydrastis canadensis) against selected oral pathogens. Planta Med. 2003;69(7):623-7.

Inbaraj JJ, Kukielczak BM, Bilski P, et al. Photochemistry and photocytotoxicity of alkaloids from Goldenseal (Hydrastis canadensis L.). 2. Palmatine, hydrastine, canadine, and hydrastinine. Chem Res Toxicol. 2006;19(6):739-44.

Janbaz KH, Gilani AH. Studies on preventive and curative effects of berberine on chemical-induced hepatotoxicity in rodents. Fitoterapia. 2000;71:25-33.

Lau CW, Yao XQ, Chen ZY, et al. Cardiovascular actions of berberine. [review]. Cardiovasc Drug Rev. 2001;19(3):234-244.

Li H, Miyahara T, Tezuka Y, et al. Effect of berberine on bone mineral density in SAMP6 as a senile osteoporosis model. Biol Pharm Bull. 2003;26(1):110-1.

Mahady GB, Pendland SL, Stoia A, et al. In vitro susceptibility of Helicobacter pylori to isoquinoline alkaloids from Sanguinaria canadensis and Hydrastis canadensis. Phytother Res. 2003;17(3):217-21.

Palanisamy A, Haller C, Olson KR. Photosensitivity reaction in a woman using an herbal supplement containing ginseng, goldenseal, and bee pollen. J Toxicol Clin Toxicol. 2003;41(6):865-7.

Periera da Silva A, Rocha R, Silva CM, et al. Antioxidants in medicinal plant extracts. A research study of the antioxidant capacity of Crataegus, Hamamelis and Hydrastis. Phytother Res. 2000;14(8):612-616.

Sandhu RS, Prescilla RP, Simonelli TM, et al. Influence of goldenseal root on the pharmacokinetics of indinavir. J Clin Pharmacol. 2003;43(11):1283-8.

Scazzocchio F, Cometa MF, Tomassini L, et al. Antibacterial activity of Hydrastis canadensis extract and its major isolated alkaloids. Planta Med. 2001;67(6):561-564.

Weber HA, Zart MK, Hodges AE, et al., Chemical comparison of goldenseal (Hydrastis canadensis L.) root powder from three commercial suppliers. J Agric Food Chem. 2003;51(25):7352-8.