The herb coltsfoot has a long history of use in the herbal medicine of Europe and Asia as a treatment for coughs and sore throats. It does not appear that traditional herbalists recognized that this treatment, which they often recommended for use by children, may cause liver damage.

Germany’s Commission E, the scientific body assigned to approving the use of herbal treatments in Germany, once approved coltsfoot for the treatment of sore throat.1 However, coltsfoot was subsequently banned due to its content of potentially liver-toxic substances called pyrrolizidine alkaloids (see Safety Issues).2

Safety aside, there is no meaningful evidence that coltsfoot has any medicinal effects. Only double-blind, placebo-controlled trials can prove a treatment effective, and none have been reported for coltsfoot. (For information on why this type of study is essential, see Why Does This Database Rely on Double-blind Studies?) Interestingly, much the same situation prevails for conventional cough syrups, none of which have been proven effective.3 However, they at least appear to be safe.