Echinacea Supplements Review
Initial Posting: 2/28/16 Last Update: 6/20/19
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What It Is:
- Echinacea supplements may modestly help prevent colds when taken during cold season and/or reduce the severity of a cold if taken at the first onset of symptoms (See What It Does).
- Phenolic compounds in Echinacea may be responsible for some of the herb's effects (See What It Is).
- ConsumerLab.com found that two products did not contain the expected minimum amounts of total phenolic compounds (TPCs), one product exceeded a limit for lead contamination, and another product failed to properly label its Echinacea. (See What CL Found).
- Among 10 products Approved for Quality by ConsumerLab.com, three were chosen as Top Picks>>.
- Echinacea comes in various forms and concentrations, but most positive clinical studies used products extracted from aerial parts (leaves, flowers, stems) of E. purpurea, often dried into extract powders (900 mg per day taken in 3 divided doses). (See What to Consider When Buying and Using).
- Echinacea appears to be relatively safe for short-term use (up to 12 weeks) and side-effects tend to be mild (GI symptoms, increases urination). However, be aware that some people may be allergic, and rarely, liver damage has been reported (See Concerns and Cautions).
Echinacea — commonly known as purple coneflower — is a group of nine related plant species indigenous to North America. Three species of Echinacea —Echinacea purpurea, E. angustifolia, and E. pallida have been used medicinally and are commonly found in dietary supplements. Supplements can be made from the above-ground herb (aerial) and/or root portions of the plant, or a combination of both. Compounds known as phenols (including cichoric and caftaric acids and echinacoside) are known to exist in Echinacea and have been shown to inhibit steps in the development of inflammation. The main phenolic compound, cichoric acid, also shows immunostimulatory properties (Georgieva, J Exp Int Med 2014). Other constituents that may be important include alkamides (such as isobutylamides) and polysaccharides.
What It Does:
Echinacea's popularity is primarily due to its ability to reduce the symptoms and duration of colds and flu-like illnesses. It is believed to work through modulation of the immune system. The German Commission E, World Health Organization (WHO) and Canadian Natural Health Products Directorate have all advocated the use of Echinacea for upper respiratory tract symptoms related to the common cold; however the results of clinical trials have been mixed.
Part of the difficulty in comparing the results of clinical trials (and perhaps the reason for varying results) with Echinacea is that studies use varying doses, species and parts of the Echinacea plant. The different species and plant parts used can contain different concentrations of compounds, and even the same plant, like all plants, may contain differing levels of these compounds at different times of the year or in different geographical locations (Qu 2005). It is yet to be determined if it is one, a few, or the combined effect of many constituents that are responsible for Echinacea's immune-modulating properties.
Another difficulty is that studies employ Echinacea at varying times in the course of a cold: prophylactically before a cold begins; at the first symptoms of a cold; and/or several weeks after a cold, all of which could impact the herb's effectiveness.
In 2007 a meta-analysis (in which results of many clinical trials are pooled and analyzed) showed prophylactic use of Echinacea reduced the incidence of colds by 65%, but by only 35% if taken at the first sign of symptoms (Shah 2007). A 2008 report showed that taking an E. purpurea extract during the winter months did not significantly prevent the onset of upper respiratory tract infections versus placebo (O'Neil 2008). This study, however, did not list the part of the Echinacea plant used nor did it indicate analytical work to confirm the contents. A large controlled trial (Barrett 2010) giving a five-day course of Echinacea at the first sign of symptoms, failed to show a substantial benefit. That study used tablets made by MediHerb (distributed in the U.S. as Echinacea Premium by Standard Process) containing dried extracts of E. purpurea and E. angustifolia root. However, a liquid extract of E. angustifolia root was shown to help in the prevention of upper respiratory tract infections (Melchart 1998).
The most recent and largest study of Echinacea suggests it to be modestly effective at preventing colds if taken three times daily throughout the cold season (and 5 times daily during a cold) (Jawad, Evid Based Compl Alt Med 2012). Compared to those taking placebo, the Echinacea-treated group experienced 26% fewer cold "events" (colds and days spent with colds, combined). In addition, there were fewer recurrent colds among those treated and they took less pain medication, such as aspirin, during colds. The study used a liquid supplement (Echinaforce from A. Vogel Bioforce AG, which is among the products tested in the review below although it was Not Approved). Drops of Echinaforce were diluted in water and retained in the mouth for 10 seconds before being swallowed "to provide maximum local antiviral effects," according to the study. Most people were not 100% compliant with the treatment, but those who were experienced even greater reductions in colds.
Several small, company-funded studies suggest that taking 6 tablets of Esberitox (marketed in the U.S. by Enzymatic Therapy and sold in Europe as Esberitox N) three times daily during a cold or respiratory tract infection may hasten improvements in symptoms (i.e. nasal congestion, hoarseness, chest pain) by about one to three days -- especially when taken at the earliest onset of symptoms (Zepelin, Curr Med Res Opin 1999; Naser, Phytomedicine 2005). Among adults with acute exacerbation of chronic bronchitis who took an antibiotic,
those who also took liquid Esberitox N drops 3 times daily (a total daily dose of 8.8 mL) for 28 days were breathing slightly better at day 10 of treatment than those given placebo (Hauke, Chemotherapy 2002). Esberitox is a blend of extracts of E. purpurea and E. pallida root, wild indigo (Baptisia tinctorial) root, and Thuja occidentalis leaf (an ingredient which may potentially cause seizers in people with seizure disorder (Millet, Clin Toxicol 1981). No serious adverse events were reported in these studies; mild to moderate side effects such nausea and insomnia were reported by a small number of participants.
Two small studies (by the same research group) showed that an Echinacea root extract (Anxiofit-1 from Anxiofit Ltd., standardized to 3% echinoside) decreased anxiety scores in patients with subthreshold/mild anxiety and generalized anxiety disorder. However, a panel of the European Foods Safety Authority (EFSA) that reviewed these studies considered them insufficient to establish a cause and effect relationship and, therefore, refused to grant the product the right to claim that it could reduce subthreshold and mild anxiety (EFSA J, 2016).
See ConsumerTips™ for information about more dosing and usage.
Quality Concerns and What CL Tested for:
Neither the U.S. Food and Drug Administration (FDA), nor any other federal or state agency, routinely tests Echinacea products, nor any supplement, for quality prior to sale.
A quality concern with herbal supplements is potential contamination with heavy metals such as lead, cadmium and arsenic. Even if ingested at low levels, heavy metals can accumulate and cause damage over time. Cadmium, for example, builds up in kidneys and, if it reaches a high enough level, can cause kidney damage. Lead, which accumulates in bones, can cause a variety of symptoms including abdominal pain, impaired mental functioning, high blood pressure and anemia.
Another concern with herb and root powders is contamination with Escherichia coli, Salmonella spp., Staphylococcus aureus and Pseudomonas aeruginosa and mold which can occur during growing, harvesting or preparation as a supplement. As a result, the WHO has established standards for Salmonella contamination of medicinal plant materials intended for internal use. Furthermore the U.S. Food and Drug Administration (FDA) has established zero tolerance levels for Salmonella.
ConsumerLab.com, as part of its mission to independently evaluate products that affect health, wellness, and nutrition, purchased many Echinacea purpurea and angustifolia supplements sold in the U.S. and tested all of them to determine whether they 1) possessed the claimed and minimum expected amount of total phenolic compounds (TPCs), 2) if products containing herb or root powders were free of unacceptable levels of lead, cadmium, and arsenic and 3) if products containing herb or root powders were free of contamination with Escherichia coli, Salmonella spp., Staphylococcus aureus and Pseudomonas aeruginosa and mold (see Testing Methods and Passing Score).