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Echinacea purpurea is a herb commonly used either in response to or daily for prevention of the common cold. It may hold benefit in doing so, although it outperforms placebo unreliably and the amount of benefit derived is similarly unreliable.

Our evidence-based analysis on echinacea features 133 unique references to scientific papers.

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Summary of Echinacea

Primary Information, Benefits, Effects, and Important Facts

Echinacea is a herbal supplement that is commonly used either at the first signs of sickness (in an attempt to accelerate the rate of recovery) or daily as a preventative supplement in persons who are sick frequently (in hopes of reducing the frequency of which they get sick). The term 'echinacea' refers to a genera of plants, and a few species in this family including purpurea and angustifolia are desired due to their alkylamide content (seen as the active ingredients).

Overall, echinacea appears to be somewhat effective for fighting off sickness and accelerating the rate of recovery in sickness but both of these claims are highly variable. There are trials suggesting remarkable recovery rates, and there are trials suggesting no benefits whatsoever. When looking at meta-analyses on the topic, there appears to be a positive and protective effect of echinacea on sickness frequency (in those who are frequently sick) and in accelerating the rate of recovery; the effect size, however, is not large. When looking at the severity of sickness or symptoms of the cold, echinacea does not appear to have any significant influence (unlike something like andrographis paniculata).

The mechanisms are thought to either be due to macrophage stimulation (which although the alkylamides can stimulate macrophages via cannabinoid receptors, contamination of supplements with lipopolysaccharide/LPS appears to be the main stimulatory) or from producing more antigen-specific immunoglobulins.

This variability is likely due to the alkylamide mixture, where the term 'alkylamide' refers to over 20 similarly structured compounds that vary in their ratios to one another from one batch of echinacea to the next (due to growing conditions, usually), although some context-dependent effects of echinacea cannot be ruled out.

Overally, echinacea may be the best option available at this time but by no means is a highly reliable intervention for reducing cold frequency or sickness length.

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How to Take

Medical Disclaimer

Recommended dosage, active amounts, other details

For dehydrated powders (including encapsulated echinacea) the species of purpuera tends to be used and oral doses are taken upwards of 300mg thrice a day (900mg daily) and 500mg thrice daily (1,500mg daily).

Tinctures of an ethanolic extract of the aerial parts (leaves and stems) appears to be used in the concentration of 2.5mL thrice a day or up to 10mL daily.

There is no much evidence as to whether these are the optimal doses, and studies seem to be very hetereogeneous in their benefits due to lack of standardization.

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Human Effect Matrix

The Human Effect Matrix looks at human studies (it excludes animal and in vitro studies) to tell you what effects echinacea has on your body, and how strong these effects are.
Grade Level of Evidence
Robust research conducted with repeated double-blind clinical trials
Multiple studies where at least two are double-blind and placebo controlled
Single double-blind study or multiple cohort studies
Uncontrolled or observational studies only
Level of Evidence
? The amount of high quality evidence. The more evidence, the more we can trust the results.
Outcome Magnitude of effect
? The direction and size of the supplement's impact on each outcome. Some supplements can have an increasing effect, others have a decreasing effect, and others have no effect.
Consistency of research results
? Scientific research does not always agree. HIGH or VERY HIGH means that most of the scientific research agrees.
grade-a Notable Very High See all 6 studies
Although a high variability exists, the meta-analysis has concluded a 1.4-day reduction in sickness when it occurs relative to placebo. As echinacea is also a comparator for sickness, this reduction in notable
grade-a Notable High See all 11 studies
The reduction in rate of sickness seen with echinacea as a daily supplement is highly effective in some instances, but subject to a high degree of variability. It is notable due to it being a comparator.
grade-b - Very High See all 4 studies
Insufficient evidence to support modification of symptoms of sickness
grade-c Minor - See study
Lone trial noted an increase in EPO production without an accompanying increase in red blood cell count; practical significance of these results uncertain
grade-c Minor - See study
Possible effects, but study assessed salivary IgA (biomarker of immunity) and not sickness rates; hard to assess potency.
grade-c Minor - See study
Effective, but to a small degree based on one trial.
grade-c Minor - See study
Not an astounding increase in VO2 max, requires replication.
grade-c - - See study
No significant known effects on blood pressure
grade-c - - See study
Oddly ineffective despite an increase in erythropoetin seen
grade-c - - See study
Likely related to the inefficacy in treating symptoms, but no significant ability to aid in sleep quality during or without sickness

Studies Excluded from Consideration

  • Excluded due to being confounded with the inclusion of other nutrients[1][2][3]

  • Duplicated[4]

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Things to Note

Is a Form Of

Primary Function:

Also Known As

Brauneria purpurea, Echinacea intermedia, Rudbeckia purpurea, Purple coneflower herb, Coneflower, red sunflower

Caution Notice

It is possible to be allergic to echinacea as a plant, and this may be related to ragweed allergies.

  • After processing, echinacea bioactives may be sensitive to light and heat. It may be prudent to store echinacea in a cool (5°C or lower) and dark place

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Click here to see all 133 references.