Goldenseal (Hydrastis canadensis ) is a perennial plant that grows deep in the woods from Vermont to Arkansas. Cherokee Indians used its golden roots as a yellow dye, for skin problems, and as an eyewash. After the Civil War it was such a popular ingredient in medicines that it nearly became extinct. Today it's still quite rare and expensive, and many herbalists discourage its use because of the lack of evidence for its safety and effectiveness.
What is it good for?
There are few published studies supporting any medicinal use for goldenseal. Folkloric claims suggest that swishing goldenseal tea around in your mouth can soothe canker sores. A chemical found in the herb also shows up as an ingredient in sterile eyewashes. Though it is often sold in combination with echinacea as an immune booster, there is no evidence to support this claim. And studies have shown that goldenseal does not prevent the detection of morphine, marijuana, cocaine or other drugs in urine samples.
How does it work?
The two compounds that give goldenseal its yellow color, hystrastine and berberine, are also mild astringents and antiseptics that may make the herb modestly effective at soothing mouth sores.
How safe is it?
If you do use goldenseal tea as a mouth rinse, don't swallow it and only use it for a short time. Although small amounts can be ingested without side effects, larger doses or long-term use can cause throat irritation, vomiting, and diarrhea. Large amounts of hydrastine can dangerously increase blood pressure, causing convulsions and even death. Pregnant women should be careful to stay clear of goldenseal. Exposure might cause problems in newborns and some animal studies have shown that berberine may stimulate uterine contractions.
What's the best way to take it?
The government does not regulate herbal remedies as strictly as it does drugs, so it's hard to know what you're getting. There's no required testing for safety and effectiveness, for example. Quality and potency can vary from product to product. Most health food stores carry the root and its extracts in tinctures, capsules, and teas, but because true goldenseal is hard to come by, the products you see on store shelves are often adulterated with other herbs.
Chan E. Displacement of bilirubin from albumin by berberine. Biol Neonate 1993;63(4):201-8.
Drug Digest. Goldenseal. November 2004.