The Cherokees used the roots and rhizomes of the plant to treat skin diseases and relieve sore eyes. Today, goldenseal is still used as an external wash for canker sores and skin wounds, but most people take it internally, usually in capsule form, to soothe inflamed mucous membranes, stop or slow down infections, and stimulate digestion, says Jennifer Brett, N.D., a naturopathic doctor at the Wilton Naturopathic Center in Stratford, Connecticut. It is frequently recommended for ulcers in the upper intestine and especially advocated for respiratory infections, she says.

"It seems to be really effective for upper respiratory infections like sore throats and sinus infections," says Dr. Brett. "It has the ability to stimulate your immune system and slow down the rate at which bacteria invade your cells and tissues."

If used early, goldenseal is effective against nearly any kind of infection, from a sore throat to a cut on the hand, says Dr. Brett. Its antibacterial and antiseptic properties can help fight off bacteria. While that doesn’t mean that goldenseal should be used in place of an antibiotic when one is needed, "it can help keep an infection from spreading long enough so that your immune system can take care of it," she says. "If the infection has really set in, though, you may need more help than goldenseal can give you."

Goldenseal can make the symptoms of an infection less bothersome. It’s especially effective in reducing phlegm and drying up secretions from inflamed mucous membranes, the tissues that make up the inner lining of the body, explains Dr. Brett. When you have an irritated sinus or a sore throat from postnasal drip, the herb can bring great relief, Dr. Brett says. "It works best when you can get the goldenseal right on the infection. I tell people to gargle with a tea of goldenseal when they have a sore throat."

In olden days, people generally put goldenseal root into water and brewed a tea, but it was a bitter tonic to swallow. Even rinsing out your mouth with goldenseal can be a memorably unpleasant experience. Herbalists classify it as a potent, bitter, astringent herb, and it simply tastes terrible, says Alison Lee, M.D., a pain-management specialist and medical director of Barefoot Doctors, an alternative medicine practice in Ann Arbor, Michigan.