Assertion: comfrey's use | /r/HasProperty | gardner
Facets:
Source sentences:
text: That being said, based on case reports of liver disease in individuals taking the leaf or root of unspecified Symphytum species, the American Herbal Products Association (AHPA) did ban the sale of botanical products containing toxic PAs (including those with Russian comfrey and prickly comfrey) for internal use, suggesting those products should be restricted to external use (Gardner & McGuffin, 2013).