Echinacea is one of the most popular herbs in America today. Echinacea is a Native American medicinal plant named for the prickly scales in its large conical seed head, which resembles the spines of an angry hedgehog (echinos is Greek for hedgehog).

Archaeologists have found evidence that Native Americans may have used echinacea for more than 400 years to treat infections and wounds, and as a general "cure-all." Throughout history people have used echinacea 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, most of the scientific research on echinacea has been conducted in Germany.

Today, people use echinacea to shorten the duration of the common cold and flu, and reduce symptoms, such as sore throat (pharyngitis), cough, and fever. Many herbalists also recommend echinacea to help boost the immune system and help the body fight infections.

General Uses

Several laboratory and animal studies suggest that echinacea contains active substances that boost immune function, relieve pain, reduce inflammation, and have hormonal, antiviral, and antioxidant effects. For this reason, professional herbalists may recommend echinacea to treat urinary tract infections, vaginal yeast (candida) infections, ear infections (also known as otitis media), athlete's foot, sinusitis, hay fever (also called allergic rhinitis), as well as slow-healing wounds. Preliminary studies in the lab suggest echinacea may help inhibit colon tumors when combined with cichoric acid. One study even suggests that echinacea extract exerted an antiviral action on the development of recurrent cold sores triggered by the herpes simplex virus (HSVI) when taken prior to infection.

Common Cold

Whether or not echinacea helps prevent or treat the common cold remains controversial. Some studies have shown that the herb can make you feel better faster. Others suggest that echinacea has no impact on a cold at all. Several clinical trials have shown that people who take echinacea as soon as they feel sick reduce the severity of their cold and have fewer symptoms than those who do not take the herb. One study of 95 people with early symptoms of cold and flu (such as runny nose, scratchy throat, and fever) found that those who drank several cups of echinacea tea every day for 5 days felt better sooner than those who drank tea without echinacea.

A review of 14 clinical trials found that echinacea reduced the odds of developing a cold by 58% and the duration of a cold by 1 to 4 days. However, some experts dispute these findings claiming there were several weaknesses in the analyses. Echinacea preparations tested in clinical trials differ greatly. It is important to choose a high-quality echinacea supplement, and to use echinacea as early as possible in the course of a cold, with multiple doses per day for the first few days. Talk to your health care provider for recommendations.

Echinacea is a perennial herb native to the midwestern region of North America. It has tall stems, bears single pink or purple flowers, and has a central cone that is usually purple or brown in color. The large cone is actually a seed head with sharp spines that resemble a stiff comb.

Echinacea contains several chemicals that 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 those in 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 combination of these active substances is responsible for echinacea's beneficial effects, though research suggests that the above ground portion of Echinacea purpurea is the most effective.

In Germany (where herbs are regulated by the government), the above-ground parts of Echinacea purpurea are approved to treat colds, upper respiratory tract infections, urinary tract infections, and slow-healing wounds. The root of the Echinacea pallida plant is also approved for the treatment of flu-like infections.

Three species of echinacea are commonly used for medicinal purposes: Echinacea angustifolia, Echinacea pallida, and Echinacea purpurea. Many echinacea preparations contain one, two, or even all three of these species. Different products use different parts of the echinacea plant, which is why the effectiveness of echinacea may differ from one product to another.

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

A study performed by ConsumerLab.com (an independent company that tests the purity of health, wellness, and nutrition products) found that of 11 brands of echinacea purchased for testing, only 4 contained what was stated on their labels. About 10% had no echinacea at all; half were mislabeled as to the species of echinacea in the product; and more than half of the standardized preparations did not contain the labeled amount of active ingredients.

Buy products made by reputable, established companies that distribute their products through trustworthy and knowledgeable establishments. When possible, select products with guaranteed potency or standardized extracts.

Pediatric

You should work with your child's pediatrician or an herbal practitioner trained in children to determine pediatric dosing.

Use alcohol-free preparations for children.

Adult

For general immune system stimulation, during colds, flu, upper respiratory tract infections, or bladder infections, take echinacea 3 times a day until you feel better, but not for more than 10 days.

DO NOT take echinacea on an empty stomach. Instead, take it with food or a large glass of water.

Apply creams or ointments for slow-healing wounds as needed.

The use of herbs is a time-honored approach to strengthening the body and treating disease. However, herbs contain active substances that may trigger side effects and interact with other herbs, supplements, or medications. For these reasons, you should take herbs only under the supervision of a health care provider knowledgeable in the field of botanical medicine.

People 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 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. People with allergies to plants in the daisy family (compositae) should not take Echinacea without the supervision of a provider.

Minor side effects can include stomach upset, nausea, dizziness, and dry eyes.

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 temporary numbing and tingling on the tongue.

Despite concerns that echinacea may be unsafe for pregnant or breastfeeding women, evidence suggests that the use of echinacea during pregnancy does not increase the risk of birth defects or other pregnancy related health problems. More research is needed. In the meantime, avoid using Echinacea during pregnancy or breastfeeding until more conclusive studies are conducted.

Talk to your doctor if you have questions.

If you are taking any prescription medications, including medications used during surgery, such as anesthesia medications, you should talk to your doctor before taking echinacea. Some of the well-known interactions include the following:

• 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, treating cancer and suppressing the immune system following organ transplant so that the new organ is not rejected. Because echinacea can enhance immune function, people should not use the herb with immunosuppressive medications, especially when taken for organ transplant.
• Caffeine. Echinacea may increase the amount of time it takes for the body to break down caffeine, and therefore, increas the amount of time caffeine stays in the body.

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