how long do dried medicinal herbs last?!

Best Answer - Chosen by Voters

It depends greatly on what conditions they are stored in and what part of the herb it is. Leafy green parts age the most quickly, while bark and roots last quite a long time. Moisture, sunlight, and exposure to high temperatures all age herbs quickly. Think 6 months to a year under great conditions before they start loosing their vitality. This does not necessarily mean that they are useless; I once alleviated a sinus infection with five year old goldenseal root.

http://www.agelessherbs.com/index.html
http://www.getstuckonacupuncture.com/ind…

You are trying to apply the science based pharmaceutical concept of expiration dates to herbal drugs. It doesn't work that way - herbal drugs do not undergo the same testing or controls as pharmaceuticals. Herbal drugs are unstandardized and uncontrolled; they are crude drugs and their potency is subject to wide variation. There is little or no data about shelf life or best storage conditions, and if you've ever bought herbs from the Chinese markets you'd have noticed the less than ideal conditions in which they are kept. In order to advise expiration dates, one must first establish the 'date of manufacture', and that is not possible with herbs. They may have been hanging around the supplier's warehouse for years before they make it to the end user - no one could ever really know.