Echinacea is a popular herb used primarily to reduce the symptoms and duration
of colds and flu-like illnesses. It is believed to work through short-term
stimulation of the immune system. It has not, however, been proven effective in
preventing disease and is not recommended for long-term use, since the practice
may actually depress the immune system.
There are three species of echinacea
E. purpurea, E. angustifolia, and E. pallida. Supplements are made from the
above-ground herb (or aerial) portion and/or root portions of echinacea
depending upon the species used. Like many other herbal remedies, it is not
clearly understood which of echinacea's many chemical components are
responsible for its effects. However, the various species of echinacea have
been characterized as possessing certain marker compounds of the chemical class
called "phenols." For example, cichoric and caftaric acids are phenols found
within both the aerial and root portions of E. purpurea, while echinacoside is
a phenol found in higher levels specifically within E. angustifolia and E.
pallida roots. These compounds can be used as markers to evaluate the quality
of echinacea in a product.
Microbial contamination can sometimes occur
with herbal products such as Echinacea during their growing, harvesting or
production and the presence of microbes can also indicate decomposition of the
plant material. As a result, the World Health Organization (WHO) has
established standards for microbial contamination of medicinal plant materials
intended for internal use, and the U.S. Food and Drug Administration (FDA) has
established zero tolerance levels for certain disease-causing bacteria.
However, neither the FDA nor any other
federal or state agency routinely tests echinacea products, or other
supplements, for quality prior to sale. ConsumerLab.com, as part of its mission
to independently evaluate products that affect health, wellness, and nutrition,
purchased many of the echinacea dietary supplements sold in the U.S. and tested
them for the quality and quantity of their echinacea and levels of microbial
Results: In October and November 2000, ConsumerLab.com purchased
a total of 25 echinacea products. Six of these products were eliminated from
the testing portion of the review due to inadequate ingredient labeling.
Specifically, three did not identify the species of echinacea, one did not
state the part of the plant used, and two liquids or tinctures did not state
the concentration of echinacea. Since March 1999 the FDA has required that
labeling on herbal products provide such information.
Among the remaining 19 products, twelve
claimed to contain E. purpurea only, two claimed E. angustifolia only, and five
were mixtures of two or more species of echinacea. Some of these products also
contained other ingredients such as goldenseal. Only three of the products
tested specifically indicated the levels of phenols.
The products were tested to determine
whether they possessed 100% of the claimed amounts and types of echinacea, as
well as claimed levels of phenols. If the phenol levels were not clearly
labeled, products were held to specific minimum standards selected by
ConsumerLab.com consistent with clinical research on echinacea. Products were
also required to meet purity requirements for microbial
Among the 19 products tested,
five did not pass
testing as described below:
Two of the twelve E. purpurea-only products
tested failed. One, an extract made from aerial portions of the plant, had only
54% of the minimum expected level of total phenols. The other, a root powder,
had nearly three times the acceptable level of microbes, set by WHO. The
microbes found were aerobic bacteria, indicative of potential decomposition of
the product (not coliform bacteria, associated with fecal contamination and the
cause of gastrointestinal disease). Interestingly, the other 10 E. purpurea
products that passed testing were all made of whole herb prepared from aerial
portions (flower, leaves, and stems).
Both of the E. angustifolia-only
products failed. One, made from root powder, had no detectable levels of
echinacoside, a known marker for this species. The other, a root extract, had
less than one-third of the "4%" phenol content claimed on the label.
One of the combination products failed
because it lacked detectable levels of echinacoside, although it claimed to
contain E. angustifolia root extract.
In summary, out of the 25 products
originally purchased, only 14 products (56%) passed this review. It is possible
that the products that did not contain the expected levels of markers were made
from other types of echinacea or, perhaps, contained other ingredients
Examples of some of the products that
passed ConsumerLab.com's independent testing of Echinacea dietary
(Listed below in order of Product Name,
Amount, Type of Echinacea per Pill, and Manufacturer or
Herbal Authority Echinacea 400 mg Herbal
Supplement (400 mg E. purpurea root powder)
Manufactured by: Herbal
Authority, a division of Puritan's Pride
Natural Echinacea 400 mg (400 mg E. purpurea root powder) Manufactured by
Nature's Bounty, Inc.
Nutrilite® Triple Guard Echinacea (168.7
mg E. purpurea root and aerial powder and E. angustifolia root
powder) Mfd. By Nutrilite, a Division of Access Business Group
Tom's of Maine® Natural Echinacea Tonic With
Green Tea Liquid Herbal Supplement, Ginger-Orange (1,015 mg/15 mL of E.
purpurea (fresh root and dried aerial) powder, E. angustifolia (dried root)
extract) Tom's of Maine