PART: Root

FORMS: Powder, capsules, liquid extract

USES: (Internal) diarrhea, bladder infection, inflammation, colds and flu, gastritis, Candida overgrowth. (External) wounds, herpes, skin disorders, eyewash; works as insect repellent

DAILY DOSE: 1/2-1 tsp. per day (powder prepared as tea); 1 or 2 droppers full liquid extract; 2 capsules (2 or 3 times)

COST (for a 10-day supply): $5-$9 (powder); $8-$12 (capsules, liquid extract)

CAUTIONS: Avoid extended use (more than 10 days) and high doses. Do not take during pregnancy. Reduces the effect of the blood thinner heparin and may interfere with absorption of B vitamins.

Sore throat? Coming down with the flu? It may be time for some bitter Native American medicine known as goldenseal. Despite its foul taste, the immune-stimulating herb -- often combined with echinacea to treat colds, flu, Candida overgrowth and the infections underlying diarrhea and bladder problems -- is so popular and overharvested that it's an endangered plant species. Fortunately, goldenseal's chief antimicrobial components, berberine and hydrastine, are found in many other herbs commonly used in Chinese and Indian medicine. Studies show that berberine inhibits the growth of parasites such as Giardia and bacteria that cause acute diarrhea such as Shigella, E. coli and Salmonella. Because berberine prevents streptococci bacteria from attaching to the throat lining, goldenseal can help treat strep throat (but also see a doc). And the herb's strong astringent and anti-inflammatory effect on mucous membranes makes it especially useful for treating cold and flu symptoms. For PWAs with the sniffles, a little goldenseal for a few days may go a long way toward relief.