Commonly called purple coneflower, echinacea is used in medicinal preparations for treatment of colds
During the winter cold season, many people turn to
echinacea supplements to boost their immunity and fight off
illness. In 2004, a U.S. government survey found that
echinacea was the nation’s most popular herbal
medicine, used by 40 percent of those who bought herbal
But echinacea’s effectiveness was called into
question last July, when the New England Journal of
Medicine published the results of a large clinical trial
that found the herb did not help treat or prevent colds.
The study, funded by the National Center for Complementary
and Alternative Medicine (NCCAM), made headlines across the
country, most of them declaring the end of echinacea as a
Does that mean you should throw away the echinacea in your
medicine cabinet Not so fast, says Mark Blumenthal,
executive director of the American Botanical Council (ABC),
a nonprofit organization that promotes research and
education on medicinal plants.
“The study was well conducted; it was very well
controlled, but this is not the definitive study,”
Blumenthal says. “It needs to be seen in the context
of the many other trials of echinacea.” The ABC,
which publishes in-depth reference information on medicinal
herbs, has posted research on echinacea at
www.herbalgram.org. Among the 21 studies listed, 18 found
positive results, with three finding no significant
As the researchers themselves noted in the NCCAM study,
it’s difficult to prove or disprove that echinacea
fights colds because so many forms of the herb are used.
Commonly called purple coneflower, echinacea is a genus
with three different species that are used
medicinally—Echinacea purpurea, E. pallida, and E.
angustifolia. Medicinal preparations may contain either the
root or the aboveground portion of the plant from any of
these species, and they may be prepared as dried herbs
available in capsules, liquid extract sold as a tincture,
or even dried extracts. Even the geographic location of the
plant and the time of year it was harvested can affect its
chemical composition, according to the researchers who
conducted the NCCAM study.
For that trial, the researchers used a tincture of E.
angustifolia root three times a day in dosages that were
equivalent to 300 milligrams. The trial was conducted on
437 college students who were given cold viruses and then
sequestered in hotel rooms. Those given extracts of E.
angustifolia did not display any fewer infections or
shorter duration of the cold symptoms than those who did
not receive the herb; and the extracts were not any more
effective when given before exposure to the virus than they
were in reducing its effects.
One of the study’s co-authors, Dr. Rudolf Bauer, told
The New York Times that different dosages, species and
preparations of echinacea should be tested, and that he
personally will continue to take echinacea.
Blumenthal says that while this study provides useful
information about this preparation of E. angustifolia at
that particular dosage, he thinks the dosage tested should
have been higher.
The 900 milligrams-per-day level was determined according
to the echinacea guidelines published for a different
species (E. pallida) by Commission E—a German
government committee that compiled a widely used reference.
But more recent standards, including those set by the World
Health Organization and the Canadian National Health
Products Directorate, recommend a dosage level of 3,000
milligrams a day.
“The whole thing is about dosage,” Blumenthal
says. “It’s like taking one-third of an aspirin
and wondering why you still have a headache.”
Blumenthal’s advice is to take echinacea the same way
he does. As soon as he notices cold symptoms, Blumenthal
takes a tincture of immune-boosting herbs including
echinacea, astragalus, andrographis and elderberry syrup,
about two droppersful every two to four hours for two days.
“I take big doses right away, and usually within 24
to 36 hours, I have it knocked out.”
— Megan Phelps