Rather a sweeping statement! Actually, there are several well-conducted scientific studies which support the use of, in particular, echinacea. The situation is complicated by the fact that there has been huge diversity in the echinacea species, extraction/processing methods, and dosage regimens employed by different researchers. Undoubtedly, there are some beneficial products and treatment regimens, while others are of no value.http://www.lungusa.org/site/pp.asp?c=dvLUK9O0E&b=35873Other Remedies
Herbs and minerals such as echinacea, eucalyptus, garlic, honey, lemon, menthol, zinc, and vitamin C have gotten a lot of publicity as cold remedies. However, none of these claims are solidly supported by scientific studies.