Is there any proof that echinacea stops you getting a cold?

THE CONSENSUS IS that it does
not. A review by the Cochrane Library of
16 different trials that ran double-blind
tests on various different echinacea
preparations, found that there was no
benefit in preventing colds, compared
with taking a placebo. There is some
evidence that once you catch a cold,
echinacea might help reduce its duration
by about a day and a half The mechanism
isn’t understood and only nine of the 16
trials found a significant benefit, so the
evidence is somewhat inconsistent.
It may be that only some of
parts
the plant or some preparations have
any effect.