Should I Take an Expired Herbal Product?

I just bought 5 bottles of a product called nerve systems. It contains St John's wort, valerian root, passion flower, chamomile, kava kava and Rhodiola rosea root extract. The bottle say "use by 05/02". The people who sold it to me said it was safe since they had not gotten complaints from other customers. I'm just wondering if these products loose their potency over time.

Herbs do lose their potency over time. I recommend that you do not take a herbal product past its expiry date. Generally, herbs in dry form should be discarded one year after harvesting. Herbs in pill or capsule form lose their potency quickly. Alcoholic tinctures are usually good for 5 to 10 years, because an alcohol content of at least 25% provides an effective preservative.