Principal Proposed Uses
• Colds and Flus (Treatment, Not Prevention)
Other Proposed Uses
• Chronic Bronchitis (Acute Flare-ups) ; Genital Herpes
Probably Not Effective Uses
• Colds and Flus (Prevention) ; General Immune Support
The decorative plant Echinacea purpurea, or purple coneflower, has been one of the most popular herbal medications in both the United States and Europe for over a century.
|Native Americans used the related species Echinacea angustifolia for a wide variety of problems, including respiratory infections and snakebite. Herbal physicians among the European colonists quickly added the herb to their repertoire. Echinacea became tremendously popular toward the end of the nineteenth century, when a businessman named H.C.F. Meyer promoted an herbal concoction containing E. angustifolia. The garish, exaggerated, and poorly written nature of his labeling helped define the characteristics of a “snake oil” remedy.|
Echinacea was the number one cold and flu remedy in the United States until it was displaced by sulfa antibiotics. Ironically, antibiotics are not effective for colds, while echinacea appears to offer some real help. Echinacea remains the primary remedy for minor respiratory infections in Germany, where over 1.3 million prescriptions are issued each year.
What Is Echinacea Used for Today?
In Europe, and increasingly in the US as well, echinacea products are widely used to treat colds and flus.
The best scientific evidence about echinacea concerns its ability to help you recover from colds and minor flus more quickly. The old saying goes that “a cold lasts 7 days, but if you treat it, it will be over in a week.” However, good, if not entirely consistent, evidence tells us that echinacea can actually help you get over colds much faster. It also appears to significantly reduce symptoms while you are sick. Echinacea may also be able to “abort” a cold, if taken at the first sign of symptoms. However, taking echinacea regularly throughout cold season is probably not a great idea. Evidence suggests that it does not help prevent colds.
What Is the Scientific Evidence for Echinacea?
Reducing the Symptoms and Duration of Colds
Double-blind, placebo-controlled studies enrolling a total of more than 1,000 individuals have found that various forms and species of echinacea can reduce cold symptoms and help you get over a cold faster. The best evidence regards products that include the above-ground portion of E. purpurea.
For example, in one double-blind, placebo-controlled trial, 80 individuals with early cold symptoms were given either an above-ground E. purpurea extract or placebo. The results showed that the people who were given echinacea recovered significantly more quickly: just 6 days in the echinacea group versus 9 days in the placebo group. And, symptom reduction with a whole plant formulation of E. purpurea was seen in a double-blind, placebo-controlled study of 282 people.
But, another study found that while above-ground E. purpurea can reduce the severity of cold symptoms, the root portion may not be effective.
“Aborting” a Cold
A double-blind study suggests that echinacea cannot only make colds shorter and less severe, it might also be able to stop a cold that is just starting. In this study, 120 people were given E. purpurea or a placebo as soon as they started showing signs of getting a cold.
Participants took either echinacea or placebo at a dosage of 20 drops every 2 hours for 1 day, then 20 drops 3 times a day for a total of up to 10 days of treatment. The results were promising. Fewer people in the echinacea group felt that their initial symptoms actually developed into “real” colds (40% of those taking echinacea versus 60% taking the placebo actually became ill). Also, among those who did come down with “real” colds, improvement in the symptoms started sooner in the echinacea group (4 days instead of 8 days). Both of these results were statistically significant.
Echinacea is usually taken at the first sign of a cold and continued for 7 to 14 days. Longer-term use of echinacea is not recommended. The best (though not entirely consistent) evidence supports the use of products made from the above-ground portions of E. purpurea (specifically, flowers, leaves and stems); E. pallida root has also shown promise, but E. purpurea root appears to be ineffective.
The typical dosage of echinacea powdered extract is 300 mg 3 times a day. Alcohol tincture (1:5) is usually taken at a dosage of 3 to 4 ml 3 times daily, echinacea juice at a dosage of 2 to 3 ml 3 times daily, and whole dried root at 1 to 2 g 3 times daily. There is no broad agreement on what ingredients should be standardized in echinacea tinctures and solid extracts.
Echinacea appears to be generally safe. Even when taken in very high doses, it has not been found to cause any toxic effects.
Reported side effects are also uncommon and usually limited to minor gastrointestinal symptoms, increased urination, and mild allergic reactions. However, severe allergic reactions have occurred occasionally, some of them life threatening. In Australia, one survey found that 20% of allergy-prone individuals were allergic to echinacea.
Furthermore, a recent case report strongly suggests that use of echinacea can trigger episodes of erythema nodosum (EN). EN is an inflammatory condition that involves tender nodules under the skin. These nodules often arise after cold-like symptoms.
Two studies suggest that echinacea might interact with various medications by affecting their metabolism in the liver, but the significance of these largely theoretical findings remain unclear. A review of the research literature found no verifiable reports of drug-herb interactions with any echinacea product.