Comment on

• Treatment of the common cold with unrefined echinacea. A randomized, double-blind, placebo-controlled trial.

  Barrett BP, Brown RL, Locken K, Maberry R, Bobula JA, D'Alessio D. Barrett BP, et al. Ann Intern Med. 2002 Dec 17;137(12):939-46. doi: 10.7326/0003-4819-137-12-200212170-00006. Ann Intern Med. 2002. PMID: 12484708 Clinical Trial.