The rhizomes of P. peltatum have a long history as a medicine among native North American tribes (Penobscot Indians of Maine). They are gathered in autumn, dried and ground to a powder, the material being eaten or drunk as an infusion of the powder as a laxative or to get rid of intestinal worms. The powder was also used as a poultice to treat warts and skin growths. Currently, extracts of the plant are used in topical medication for genital warts and some skin cancers. However, the mayapple rhizome powder has a strong purgative action and the compounds in it are too toxic to attempt self-medication.