http://www.cfsan.fda.gov/~dms/qa-ind5m.html

"In some cases, herbs may be used for drug purposes and they then
become subject to the drug provisions of the Federal Food, Drug, and
Cosmetic Act discussed in Chapter II. " ? http://www.cfsan.fda.gov/~acrobat/rediiabc.pdf
?

...."If no therapeutic claims are made or implied in the labeling or
other promotional material, such products are regarded as foods and
subject only to the food provisions of the law. For example, the herb
ginseng is permitted to be sold as a tea."

...."Food and Drug Administration will prevent the marketing of herbs,
for medicinal purposes, if they have not been determined to be safe
and effective for their intended uses."
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this is a long read if anyone is up for it : http://web.health.gov/dietsupp/toc.htm
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