One of the most popular herbs in America today is the Native American medicinal plant known as echinacea. The herb is named for the prickly scales in its large conical seed head, which resemble the spines of an angry hedgehog (echinos is Greek for hedgehog).

Results of archeological digs indicate that Native Americans may have used echinacea for over 400 years to treat infections and wounds and as a general "cure-all." Echinacea has also been used throughout history to treat scarlet fever, syphilis, malaria, blood poisoning, and diphtheria. Although this herb was popular during the 18th and 19th centuries, its use began to decline in the United States after the introduction of antibiotics. Echinacea preparations became increasingly popular in Germany throughout the 20th century -- in fact, almost all of the scientific research on this herb has been conducted in this country.

Today, echinacea is primarily used to reduce the symptoms and duration of the common cold and flu and to alleviate the symptoms associated with them, such as sore throat (pharyngitis), cough, and fever. Many herbalists also recommend echinacea to help boost the activity of the immune system and to help the body fight infections.

General Uses
Several laboratory and animal studies suggest that echinacea contains active substances that enhance the activity of the immune system, relieve pain, reduce inflammation, and have hormonal, antiviral, and antioxidant effects. For this reason, professional herbalists may also recommend echinacea to treat urinary tract infections, vaginal yeast (candida) infections, ear infections (also known as otitits media), athlete's foot, sinusitis, hay fever (also called allergic rhinitis), as well as slow-healing wounds.

Common cold
Two groups of researchers recently conducted a review of the scientific literature to determine whether echinacea is safe and effective in preventing or treating the common cold. Both groups of researchers identified 13 high-quality European studies including a variety of different echinacea preparations. Nine looked at the effectiveness of echinacea to treat the common cold and four examined whether echinacea helps prevent this familiar health problem.

Most studies found that echinacea (when taken at the first sign of a cold for 8 to 10 days) reduced cold symptoms or shortened their duration. For example, in a study of 95 people with early symptoms of cold and flu (such as runny nose, scratchy throat, and fever), those who drank 5 to 6 cups of echinacea tea every day for 5 days felt better sooner than those who drank tea without echinacea. Other studies have found that echinacea reduces cold symptoms by roughly 34 percent.

One popular way that echinacea is used is to try prevent a cold or flu by taking the herb throughout cold and flu season or just after exposure to an infection via a friend or loved one. Despite the popularity of this approach, several studies suggest that it does not work. Three out of four well-designed studies found that echinacea was only "marginally" better than placebo in preventing the common cold. The last study revealed that echinacea was, in fact, no better than placebo at all in 117 healthy volunteers treated with one or the other for two weeks after being exposed to rhinovirus (a virus that often causes colds). An equal number of men and women in the placebo and echinacea groups developed a cold. The consensus seems to be that echinacea may help treat but not prevent the common cold.

Echinacea has tall stems, bears single flowers that are pink or purple, and has a central cone that is usually purplish-brown in color. The large cone is actually a seed head with sharp spines that resemble a stiff comb. Of nine echinacea species, only three are used for medicinal purposes (Echinacea angustifolia, Echinacea pallida, and Echinacea purpurea).

Many chemicals contained in echinacea play a role in its therapeutic effects. These include polysaccharides, glycoproteins, alkamides, volatile oils, and flavonoids.

The chemicals contained in the root differ considerably from the upper part of the plant. For example, the roots have high concentrations of volatile oils (odorous compounds) while the above-ground parts of the plant tend to contain more polysaccharides (substances known to trigger the activity of the immune system). The beneficial effects of echinacea appear to be due to the combination of these active substances.

In Germany (where herbs are regulated by the government), the above-ground parts of E. purpurea are approved to treat colds, upper respiratory tract infections, urinary tract infections, and slow-healing wounds. The root of the E. pallida plant is also approved for the treatment of flu-like infections. Many echinacea products available in the United States contain one, two, or even all three plant species.

There are three species of echinacea that are commonly used for medicinal purposes: Echinacea angustifolia, Echinacea pallida, and Echinacea purpurea. Many echinacea preparations available today contain one, two, or even all three of these species. Different products use different parts of the echinacea plant. For this reason, echinacea preparations vary considerably. This is why, some experts believe, the effectiveness of echinacea tends to differ from one product to the next.

Echinacea (including one, two, or all three species) is available in extracts, tinctures, tablets, capsules, and ointments. Echinacea is also available in combination with other immune-boosting herbs, vitamins, and minerals.

A recent study performed by ConsumerLab.com (an independent company that tests the purity of health, wellness, and nutrition products) found that of 25 brands of echinacea purchased for testing, only 14 (56%) truly contained what was stated on their labels. Six of the products were discarded because they were inadequately labeled according to FDA guidelines -- they did not identify the amount, species, or plant parts used. Among the 19 remaining products, two of 12 containing E. purpurea failed, with one product containing only 54% of the minimum level of active ingredients. Neither of the E. angustifolia products passed inspection. Be sure to buy products made by established companies with good reputations, and who distribute their products through trustworthy and knowledgeable establishments. Whenever possible, select products with guaranteed potency or standardized extracts.

Pediatric

Adjust the recommended adult dose to account for the child's weight. Most herbal dosages for adults are calculated on the basis of a 150 lb (70 kg) adult. Therefore, if the child weighs 50 lb (20 to 25 kg), the appropriate dose of echinacea for this child would be 1/3 of the adult dose.

Use alcohol-free preparations for children.

Adult

For general immune system stimulation, during colds, flu, upper respiratory tract infections, or bladder infections, choose from the following forms and take three times a day:

• 1 to 2 grams dried root or herb, as tea
• 2 to 3 mL of standardized tincture extract
• 200 mg of powdered extract containing 4% phenolics
• Tincture (1:5): 1 to 3 mL (20 to 90 drops)
• Stabilized fresh extract: 0.75 mL (15 to 23 drops)

For slow-healing wounds, creams or ointments should be applied as needed.

The use of herbs is a time-honored approach to strengthening the body and treating disease. Herbs, however, contain active substances that can trigger side effects and interact with other herbs, supplements, or medications. For these reasons, herbs should be taken with care, under the supervision of a practitioner knowledgeable in the field of botanical medicine.

The American Herbal Products Association gives echinacea a class 1 safety rating, which indicates that it is safe when used appropriately (as instructed by the product label) and with the guidance of a healthcare professional. In Germany, use of echinacea is restricted to no longer than eight weeks at a time. This is because after eight consecutive weeks, echinacea losses its effectiveness and may even diminish immune function. Regular users of this herb, need "break" periods – namely, periods of time that they are not taking echinacea in order for it to maintain its ability to enhance immune function and fight infection.

Individuals with tuberculosis, leukemia, diabetes, connective tissue disorders, multiple sclerosis, HIV or AIDS, any autoimmune diseases, or, possibly, liver disorders should not take echinacea. There is some concern that echinacea may reduce the effectiveness of medications that suppress the immune system. For this reason, people receiving organ transplants (who must take immunosuppressant medications [see Possible Interactions]) should avoid this herb.

In rare cases, echinacea may cause allergic reactions ranging from a mild rash to anaphylaxis (a life threatening reaction accompanied by throat tightening, shortness of breath, and, possibly, fainting). People with asthma and allergies may be at an increased risk for developing these adverse reactions.

There has been one report of an individual developing erythema nodosum (a painful skin condition) after taking echinacea to treat the flu.

When taken by mouth, echinacea may cause a temporary numbing and tingling sensation on the tongue.

Despite concerns that echinacea may be unsafe for pregnant or breastfeeding women, new evidence suggests that the use of echinacea during pregnancy does not increase the risk of birth defects or other pregnancy-related health problems.

If you are currently being treated with any of the following medications, you should not use echinacea without first talking to your healthcare provider:

Econazole
Echinacea may be useful in combination with econazole, an antifungal agent used to treat yeast infections (such as athlete's foot). When echinacea is used together with econazole, recurrence rates of these infections may be reduced.

Immunosuppressants
Immunosuppressants refers to a group of medications that are used for two main purposes -- treat cancer and suppress the immune system following organ transplant so that the new organ is not rejected. Because echinacea can enhance immune function, it is not advisable to use the herb with medications in this class, especially for organ transplant.

In terms of cancer treatment, however, a couple of test tube studies imply that echinacea may prove useful when used in conjunction with cyclophosphamide, one medication in this class. The idea is that using echinacea with this or other chemotherapy agents that act as immunosuppressants, may allow the cancer-fighting medicines to kill the tumors while the immune system continues to be protected. If this theory proves to be correct, then, echinacea could possibly prevent many of the untoward side effects of chemotherapy.

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