Echinacea purpurea, adverse effects

There are several botanicals that have purported immunostimulating effects. These include Panax ginseng and Echinacea purpurea (74), which have both been used as an immune stimulant. Any potential adverse effect on the pharmacological activity of immunosuppressants has not been reported in patients or evaluated in clinical studies. Given the lack of data, it would be prudent to advise against concurrent intake of these botanicals, and closely monitor changes in efficacy in patients who self-administer these botanicals. 

Scaglione and Lund [13] tested a combination of Echinacea purpurea root extract, vitamin C, rosemary leaf extract, eucalyptus leaf extract, and fennel seed extract vs. placebo in 32 subjects suffering from a common cold. The duration of the illness (based on the rhinorrhea) was 3.37 1.25 days in the treatment group and 4.37 1.57 days in the placebo group (p < 0.01). Patients in the treatment groups also used a significantly lower number of paper tissues. No adverse effects were observed. 

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