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Low-Dose Echinacea Trial Published in New England Journal of Medicine
Low-Dose Echinacea Trial Published in New England Journal of Medicine

The big news in the herb community in the past few months was the publication of a clinical trial on extracts of Echinacea angustifolia roots in the New England Journal of Medicine1(NEJM).

The trial was conducted on 399 college students who were inoculated (nasally) with a rhinovirus, the type associated with 30% to 50% of colds. The trial utilized 3 extracts, the chemical profile being focused on the alkamides, as determined by the internationally acknowledged Echinacea expert Prof. Rudolf Bauer at the Karl-Franzens University in Graz, Austria, and then produced by a leading European extract manufacturer. In the multi-arm trial subjects were given Echinacea (Echinacea angustifolia) extracts to determine if the Echinacea would help prevent infections and to see if it would reduce the duration and/or severity of the upper respiratory tract infections.

The resulting message to the public was predictably negative, as evidenced in these headlines: “Study Debunks Echinacea’s Powers” (CBS News); “Study Says Echinacea Has No Effect on Colds” (NY Times); “Cold Relief from Echinacea Might Be All in Your Head” (LA Times), “Study Gives Echinacea the Cold Shoulder” (MSN), “Echinacea Not a Remedy, Study Says” (AP), and “Echinacea: It Works; Oops, It Works Not” (USA Today).

The media spin tried to suggest that this was the “definitive” trial on echinacea. The primary investigator, Ronald B. Turner, MD, of the University of Virginia, was quoted in a USA Today article as saying, “It’s not clinically effective.”2

ABC’s response to the media focused on what we believed was 1 major flaw of the trial—the dosage. The subjects received 1.5 mL of the extracts (or placebo) 3 times per day, with a total daily equivalent to 900 mg of the dried root. This dosage is based on the German Commission E monograph on E. pallida root3 (there is no approved Commission E monograph on E. angustifolia root since at the time of publication in 1992 there had been no positive clinical trials on this type of Echinacea). ABC’s press release4 emphasized that the World Health Organization monograph on E. angustifolia root5notes a daily dose of 3000 mg per day of dried root or equivalent preparations, as does the draft monograph of the Canadian Natural Health Products Directorate.6 This dose is 330% higher than that used in the trial published in NEJM. (NEJM has accepted a letter-to-the-editor on this point submitted by Prof. Norman R. Farnsworth and myself.)

ABC was fortunate to obtain significant coverage in the media from our many interviews and our press release. ABC was quoted in thousands of newspapers around the world via the AP, as well as quotes in different articles in the Los Angeles Times, The New York Times, Bloomberg Business News, as well as appearances on the NBC Nightly News with Brian Williams and Wolf Blitzer Reports on CNN, and ABC information was used for a story on Anderson Cooper 360 on CNN.

In June one of the study’s co-authors, David Gangemi, PhD, of Clemson University, responding to a question about the low dosage used in the trial after his speech at the “Medicines from the Earth” symposium in North Carolina said, “I think in retrospect if we go back and we look at some of the other products that are out there maybe we’re only one tenth the level we should be” (emphasis added).7 Prof. Bauer has stated that he believes the results of this trial cannot be extended to all commercial echinacea preparations since there are 3 species and numerous plant parts and preparations types, as noted in the NEJM paper.

The results of this trial have had an impact on the public discussion regarding the prioritization of funding for clinical research on herbs. In an accompanying perspective,8 Dr. Wallace Sampson wrote that because this trial resulted in negative findings, as had some previously NCCAM-funded echinacea trials, all future government-funded research on echinacea should be terminated. And, he continued, such public funding should be curtailed to all herbs, dietary supplements, and other “implausible remedies,” including all CAM modalities.

Bernadine Healy, MD, former director of the National Institutes of Health, wrote in an editorial in US News and World Report: “Though alternative medicine does have a way of inspiring hot views among some of medicine’s finest, his [i.e., Dr. Sampson’s] commentary is less scientific analysis and more culture war. And it’s a war that, if won, would create a Catch-22, dooming the world of remedies that lack Establishment credentials to eternal ignorance and therefore discredit.”9 She continued, “The nature of medicine is seeking, finding, testing, retesting, debunking, and being utterly surprised at how often established dogma crumbles. Echinacea aficionados should take serious stock of the new study. But academics should not be too smug in dismissing the herb as the fallen icon of medicine on the fringe.”9

The award for the best sound-bite on this trial goes to Michael McGuffin, president of the American Herbal Products Association, who cogently stated in an interview on National Public Radio’s All Things Considered, “It’s like conducting a study on the effect of a third of an aspirin and wondering why you still got a headache.”


1. Turner RB, Bauer R, Woelkart K, Hulsey TC, Gangemi DJ. An evaluation of Echinacea angustifolia preparations in experimental rhinovirus infections. N Engl J Med. 2005;353:341-348.

2. Weise E. Echinacea: It works; oops, it works not. USA Today. July 27, 2005.

3. Blumenthal M, Busse WR, Goldberg A, Hall T, Riggins CW, Rister RS, eds. Klein S, Rister RS, trans. The Complete German Commission E Monographs—Therapeutic Guide to Herbal Medicines. Boston: Integrative Medicine Communications; Austin, TX: American Botanical Council; 1998.

4. Herbal Science Group Says Dosage Too Low in New Echinacea Trial [press release]. Austin, TX: American Botanical Council, July 27, 2005.

5. Echinacea Radix. In: WHO monographs on selected medicinal plants. Geneva: World Health Organization; 1999.

6. Echinacea. Natural Health Products Directorate. Health Canada. Draft January 2004. Available at: Accessed July 27, 2005.

7. Gangemi D. Medicines from the Earth [symposium]. Black Mountain, NC. June 4, 2005.

8. Sampson W. Studying herbal remedies. N Engl J Med. 2005;353:337-339.

9. Healy B. Echinacea’s War. U.S. News & World Report. August 8, 2005. Available at: Accessed September 25, 2005.