Is Comfrey a Carcinogen

Comfrey contains pyrrolizidine alkaloids that are both hepatotoxic and carcinogenic (13), and there is extensive literature concerning hepatotoxicity with use of oral comfrey (5) (6) (7) (8) (9) (10).

Is comfrey illegal to grow in the US?

The pyrrolizidine alkaloids in comfrey can cause severe liver damage, liver cancer, mutagenicity, and even death. [8,9] For this reason, the U.S. Food and Drug Administration has banned the sale of oral comfrey products in the United States.

Is comfrey poisonous to chickens?

Comfrey has been deemed safe to handle and to use externally. … Any comfrey that my hens have eaten they’ve shared with the whole flock—and they are eating commercial laying feed, too.