Many people who become interested in herbs and natural remedies began with an introduction to echinacea, an herbal remedy commonly used for treating colds. Does it really work?

What Is It?

]]>Echinacea]]> is a perennial plant that grows one to two feet in height and looks something like a Black-eyed Susan. Grown both commercially and in the wild, its flower, stem, and root are marketed in pill, liquid, or powdered form. And it is gaining in popularity: in the United States alone, it is estimated to generate upwards of $300 million in sales per year.


Originally, echinacea was used by many Midwest Native Americans for a variety of medicinal purposes (including the treatment of infections and poisonous snakebites). As early as the 1880s, echinacea came into favor among American medical practitioners. Despite the fact that in 1910 the American Medical Association dismissed echinacea as worthless, it remained popular in the United States until penicillin and other anti-infection drugs were discovered.

In the 1930s, a German doctor, Gerhard Madaus, began researching the medicinal properties of echinacea. He discovered that it contained certain complex sugar molecules, known as polysaccharides , which he believed might stimulate the immune system. Dr. Madaus also developed a juice form of echinacea (derived from the plant's flower) that became (and remains) popular.

What Does It Do?

The primary documented use of echinacea involves treatment of colds and flu, however studies are now indicating that it does not prevent or shorten the duration of colds. Substantial (but not entirely consistent) evidence suggests that echinacea lessens the severity of the symptoms while the cold or flu lasts. Echinacea does not appear to help prevent colds. Echinacea is also believed to stimulate the body’s immune system to help fight infections.

How It Works

It is not really known how echinacea works. It's thought that the herb temporarily activates the immune system. However, this is very difficult to determine at the current state of scientific knowledge. Some evidence hints that echinacea acts by doing the following:

  • Stimulating phagocytosis , the process by which white blood cells and lymphocytes consume (and thus destroy) foreign organisms in the body.
  • Increasing the rate at which the immune system ejects foreign organisms from the body.
  • Increasing the number of cells working as part of the immune system.
  • Increasing the production of interferon , a major component of the body's immune system.

Use and Dosage

Echinacea is taken at the first sign of a cold or flu for one two weeks. The best tested formulations are extracts made from the above-ground parts of the echinacea purpurea species. Echinacea purpurea root alone may not be effective. Follow label instructions for dosage. The effectiveness of other echinacea species including E. pallida and E. angustifolia has not been solidly established.

Side Effects

Limited side effects have been noted, but include allergic reactions such as rashes and increased asthma. People allergic to plant families such as the daisy or sunflower should use echinacea with caution.

When Echinacea Should Be Avoided

Echinacea has not shown significant side effects in studies. However, if in fact echinacea stimulates the immune system, it could theoretically cause harm in certain conditions. These include the following:

  • Tuberculosis
  • People taking immunosuppressive drugs for any purpose
  • Multiple sclerosis
  • Ulcerative colitis
  • Crohn's disease
  • Rheumatoid arthritis
  • Lupus
  • Asthma
  • Any autoimmune disease not mentioned above

Finally, it has also been suggested that women should avoid taking echinacea while pregnant.

Regulation of Echinacea

Since echinacea is a natural growing compound, it is covered by the Dietary Supplement Health and Education Act (DSHEA) and is not regulated by the US Food and Drug Administration (FDA). DSHEA mandates that the label of a dietary supplement must contain enough information about the composition of the product so that consumers can make informed choices. (The information must be presented in the FDA-specified format).

The manufacturer is also responsible for making sure that all the dietary ingredients in the supplements are safe. Manufacturers and distributors do not need to register with the FDA or get FDA approval before producing or selling dietary supplements, nor is its use or effectiveness substantiated by the FDA.