Organic Calamus (Acorus calamus) aka "Sweet Flag" contains an active ingredient known as asarone. To self-educate about this herb, here are some good resources: Wikipedia entry on Calamus - Erowid Calamus Vault.
Certified Organic | All Natural | Cut & Sifted
Precautions:
Specific: For external use only. Although global cultures have for a great many centuries associated consumption of calamus with long life and good health, the FDA strictly prohibits the use of Calamus in food products.