檫樹根為樟科植物檫樹Sassafras tsumu Hemsl.的根。含揮發油, 主要成份為黃樟醚 (Safrole)
https://en.wikipedia.org/wiki/Safrole
Carcinogenicity
Studies in the 1960s indicated that safrole was carcinogenic, causing permanent liver damage in animals. Consequently the US Food and Drug Administration (FDA) banned sassafras and safrole for human consumption.[5]
http://www.med126.com/pharm/2010/20100123235854_167993.shtml