- purple coneflower
- black Sampson
- Sampson root
For Patients & Caregivers
Bottom Line: Echinacea does not appear to relieve the symptoms of the common cold, but it may shorten the duration of colds when taken within 24 hours of the first cold symptoms.
We do not know exactly how Echinacea works. It has been studied in the laboratory and with animal subjects. These studies show that different immune cells are stimulated when they are incubated with Echinacea extracts. It is not known whether this same effect occurs in humans. Some compounds found in Echinacea appear to reduce inflammation, relieve pain, and kill bacteria and viruses directly.
- To treat the common cold
Most studies do not support this use. One clinical trial supports the use of Echinacea for reducing the length of colds, but not the severity of symptoms.
- As an antiseptic
Laboratory studies suggest that Echinacea has anti-bacterial qualities.
- To stimulate the immune system
Laboratory and animal studies suggest that Echinacea extracts stimulate different parts of the immune system.
- To treat viral infections
Laboratory studies suggest that Echinacea is anti-viral.
- For faster wound healing
No scientific evidence supports this use.
In a clinical trial, 128 subjects received either echinacea juice or placebo three times daily within 24 hours of the onset of cold symptoms. Participants received treatment until the symptoms were relieved or 14 days had passed. Subjects who received echinacea did not have fewer symptoms or shorter symptom duration than those receiving placebo.
A large scale randomized, placebo-controlled trial was conducted to study the effects of Echinacea angustifolia extracts as prevention and as treatment for common cold. Some subjects were given either the extracts or a placebo before exposing to rhinovirus. Others received treatment on the day of exposure. Treatments would continue for 5 more days and the severity of symptoms and other evidences of immunostimulating activities were measured. The results on 399 volunteers found E.angustifolia is no better than a placebo when used for common cold caused by rhinovirus.
- You are taking immunosuppressants such as tacrolimus or cyclosporine (Echinacea may lessen their effect)
- You have an autoimmune disorder such as systemic lupus erythematosus or rheumatoid arthritis, multiple sclerosis, other progressive collagenous disorders, tuberculosis, HIV, or AIDS (Echinacea may aggravate the disorder).
- You are pregnant or nursing
- If you are taking drugs that are substrates of Cytochrome P450 (Echinacea may increase the risk of side effects of these drugs).
- Mild stomach pain
- Dermatitis (swelling, irritation and redness of the skin)
- Anaphylaxis (a serious allergic reaction) has occurred, but rarely.
- Consumption of Echinacea resulted in exacerbation of pemphigus vulgaris in a 55-year-old man with a history of the condition, which was controlled with immunosuppressants. Only partial remission was reported after he was treated again with immunosuppressants.
- A 51-year-old woman developed asymptomatic leukopenia following chronic use of echinacea. Her white blood cell count returned to normal levels 7 months after discontinuing Echinacea supplements.
- The National Registry of Drug-Induced Ocular Side Effects received 7 reports of eye irritation and conjunctivitis following use of topical Echinacea. The symptoms resolved after discontinuing Echinacea.
- A case of severe acute hepatitis has been reported following use of Echinacea.
- Hypereosinophilia has been reported in a 58-year-old man following consumption of Echinacea. His symptoms improved after discontinuing Echinacea.
- Do not use echinacea for more than eight weeks.
- Echinacea supplements available in stores contain varying amounts and different species of Echinacea. Therefore, the beneficial results seen with Echinacea in clinical trials may not apply to a product that contains a different species or quality of this herb. One recent study found that about half of the Echinacea brands tested did not contain the type or quality of Echinacea that they claimed on the label, so shop with caution.
For Healthcare Professionals
Echinacea purpurea belongs to the family Compositae. Extracts of Echinacea derived from the root and aerial parts of the plant are widely used in Europe and USA to treat common cold. Several large scale randomized controlled trials have been conducted to evaluate Echinacea’s potential but data are conflicting.
Echinacea was shown to stimulate phagocytosis, enhance mobility of leukocytes, stimulate TNF and interleukin 1 secretion from macrophages and lymphocytes, and improve respiratory activity (2)(3) both in vitro and in vivo. The alkylamide, alkaloid, and polyacetylene fractions are thought responsible for such immunomodulatory effects (2).
Data from human clinical trials have shown that it is ineffective in preventing common cold caused by rhinoviruses (4) or in treating upper respiratory infections (5)(6)(16). Studies suggest efficacy of Echinacea/sage spray in treating acute sore throats (17). However, studies on Echinacea’ effect in reducing the incidence and duration of common cold yielded mixed results (7)(8)(9)(10)(22).
- Alkaloids: Isotussilagine, tussilagine
- Amides: Echinacein, isobutylamides
- Carbohydrates: Echinacin, polysaccharides (heteroxylan and arabinogalactan), inulin, fructose, glucose, pentose
- Glycosides: Echinacoside
- Terpenoids: Germacrane (sesquiterpene lactone ester)
- Others: Cichoric acid, betaine, methyl-para-hydroxycinnamate, vanillin, phytosterol, volatile oils
A major concern for research continues to be the lack of standardization between batches as well as the species and the parts of the plant used. An analysis of 59 brand name Echinacea products found that 48% did not contain any Echinacea whereas 10% had no measurable Echinacea. Less than half of the products met the labeled quality standards (1). Commercial products are often mixed with other species including E. angustifolia, and E. pallida.
Because of a potential for aggravation of underlying disease state, patients with autoimmune disorders such as systemic lupus erythematosus, rheumatoid arthritis, multiple sclerosis and other progressive collagenous disorders, tuberculosis, HIV, and AIDS should not consume echinacea.
- Common side effects reported from use of Echinacea are headache, dizziness, nausea, constipation, mild epigastric pain, and rash (5)(11)(12).
- Less common effects include dermatitis and anaphylaxis (13).
- A 32-year-old man developed severe thrombotic thrombocytopenic purpura (TTP) following ingestion of Echinacea to alleviate symptoms of an upper respiratory tract infection. The TTP resolved after treatment for a month (18).
- Consumption of Echinacea resulted in exacerbation of pemphigus vulgaris in a 55-year-old man with a history of the condition, which was controlled with immunosuppressants. Only partial remission was reported after he was treated again with immunosuppressants (19).
- A 51-year-old woman developed asymptomatic leukopenia following chronic use of echinacea. Her white blood cell count returned to normal levels 7 months after discontinuing Echinacea supplements (20).
- The National Registry of Drug-Induced Ocular Side Effects received 7 reports of eye irritation and conjunctivitis following use of topical Echinacea. The symptoms resolved after discontinuing Echinacea (21).
- A case of severe acute hepatitis has been reported following use of Echinacea (23).
- Hypereosinophilia has been reported in a 58-year-old man following consumption of Echinacea. His symptoms improved after discontinuing Echinacea (24).
- Immunosuppressants: Theoretically echinacea may antagonize the effects of immunosuppressants (15).
- Cytochrome P450 substrates: Echinacea inhibits CYP3A4 and can affect the intracellular concentration of drugs metabolized by this enzyme (14).
- Etoposide: Echinacea caused profound thrombocytopenia in a patient on etoposide probably due to the inhibition of CYP3A4 (25).
Yale SH, Liu K. Echinacea purpurea Therapy for the Treatment of the Common Cold. Arch Intern Med. 2004;164:1237-1241.
One hundred and twenty-eight patients participated in this trial of echinacea and upper respiratory tract infections. Patients received either 100 mg of freeze-dried juice of Echinacea purpurea three times a day or placebo. Treatment began within 24 hours of symptom onset and continued until symptoms abated or 14 days had passed. Patients were evaluated by a doctor within 24 hours of starting and completing the trial to verify symptoms. No statistically significant difference was observed between the treatment group and the control for either total symptom score or mean individual symptom score.
Turner R. et al. An Evaluation of Echinacea angustifolia in Experimental Rhinovirus Infections. N Engl J Med. 2005;353(4):341-348.
This is a randomized, placebo-controlled trial on 399 healthy volunteers to study the effects of Echinacea angustifolia extracts as prophylaxis and as treatment for common cold. Some subjects were given either Echinacea extracts or a placebo for seven days before exposure to rhinovirus while others received treatment on the day of exposure. Treatments would continue for 5 more days and the severity of symptoms; viral titers and interleukin-8 in nasal-lavage were measured. The results found no statistically significant difference between the groups that used Echinacea and the groups that used a placebo. The authors concluded that the extracts of E.angustifolia have no effects on common cold caused by rhinovirus.