What Is It
Also known as the purple, or prairie, coneflower, echinacea (pronounced ek-in-NAY-sha) is a wildflower with daisylike purple blossoms native to the grasslands of the central Untied States. For centuries, the Plains tribes used the plant to heal wounds and to counteract the toxins of snakebites. The herb also became popular with European-American pioneers and their physicians, who considered it an all-purpose infection fighter.

Of the nine echinacea species, three (Echinacea angustifolia, E. pallida, and E. purpurea) are used medicinally. They appear in literally hundreds of commercial preparations, which utilize different parts of the plant (flowers, leaves, stems, or roots) and come in a variety of forms. Echinacea contains many active ingredients thought to strengthen the immune system, and in recent years, it has become one of the most popular herbal remedies in the world.

What Does It Do
A natural antibiotic and infection fighter, echinacea helps to kill bacteria, viruses, fungi, and other disease-causing microbes. It acts by stimulating various immune-system cells that are key weapons against infection. In addition, the herb boosts the cells production of an innate virus-fighting substance called interferon. Because these effects are relatively short-lived, however, the herb is best administered at frequent intervals - as often as every couple of hours during acute infections.

Common Uses
• Reduces the body's susceptibility to colds and flu.
• Limits the duration and severity of infections.
• Helps fight recurrent respiratory, middle ear, urinary tract, and vaginal yeast infections.
• Speeds the healing of skin wounds and inflammations.

Prevention
Echinacea can help prevent the two most common viral ailments - colds and flu. It is most effective when taken at the first hint of illness. In one study of people who were susceptible to colds, those who used the herb for eight weeks were 35% less likely to come down with a cold than those given a placebo. Furthermore, they caught colds less often - 40 days elapsed between infections, versus 25 days for the placebo group. Studies confirm that echinacea is also useful if you're already suffering from the aches, pains, congestion, or fever of colds or flu. Overall, symptoms are less severe and subside sooner.

Additional Benefits
Echinacea may be of value for recurrent ailments, including vaginal yeast, urinary tract, and middle ear infections. It is also sometimes used to treat strep throat, staph infections, herpes infections (including genital herpes, cold sores, and shingles), bronchitis, and sinus infections. Moreover, the herb is being studied as a possible treatment for chronic fatigue syndrome and AIDS. And it may prove effective against some types of cancer, particularly in patients whose immune systems are depressed by radiation treatments or chemotherapy.

Echinacea can be applied to the skin as well. Its juice promotes the healing of all kinds of wounds, boils, abscesses, eczema, burns, canker or cold sores, and bedsores. To treat a sore throat or tonsillitis, the tincture can be diluted and used as a gargle.

How To Take It
Dosage: Because echinacea comes in many different forms, check the product's label for the proper dosage. For colds and flu: A high dose is needed—up to 200 mg five a times a day. In one major study, patients with the flu who were given 900 mg of echinacea a day did better than those who received either a lower dosage of 450 mg a day or a placebo. For other infections: The recommended dose is 200 mg three or four times a day. For long-term use as a general immune booster: To derive the most benefits, especially for those prone to chronic infections, alternate echinacea every three weeks with other immune-enhancing herbs, including goldenseal, astragalus, pau d'arco, and medicinal mushrooms. Echinacea teas, often blended with other herbs, are available as well.
Guidelines For Use: Echinacea should be used no longer than eight weeks, followed by a one-week interval before you resume taking it. Some studies suggest that with continuous use, the herb's immunity-boosting effects diminish. Starting and stopping echinacea, or rotating it with other herbs, may maximize its effectiveness. You can take it with or without food.

Possible Side Effects
At recommended doses, echinacea has no known side effect, and no adverse reactions have been reported in pregnant or nursing women. However, people who are allergic to flowers in the daisy family may also be allergic to this herb. If you develop a skin rash or have trouble breathing, call your doctor right away.

Shopping Hints
• Buying echinacea can be confusing because it comes in so many different forms. Experts often recommend a liquid, either the fresh-pressed juice (standardized to contain 2.4% beta-i, 2-fructofuranosides) or an alcohol-based tincture (containing a 5:1 concentration of the herb). Those who dislike the bitter taste of the liquids can take standardized extracts in pill form. Look for pills containing at least 3.5% echinacosides.
• Some commercial preparations combine echinacea with another immune-enhancing herb called goldenseal, but the combination can be very pricey. For many ailments, just plain echinacea works fine, so you can skip the more costly mixture.

Caution!
• If you're taking antibiotics or other drugs for an infection, use echinacea as an addition to, not as a replacement for, those medications.
• Echinacea can over stimulate the immune system and may worsen symptoms of lupus, multiple sclerosis, rheumatoid arthritis, or other autoimmune disorders. It may also be counterproductive in progressive infections such as tuberculosis.