Small, blue and cream, paper-wrapped package of Pennyroyal (Hedeoma Pulegloides) leaves. Pennyroyal has documented usage dating back to the ancient Greek and Roman cultures. Though pennyroyal oil is highly toxic, the plant has been used as a cooking herb, insecticide, menstruation stimulant, and abortion aid. Its use as an abortion aid and womb expeller was documented in early medical texts by notable physicians such as Pliny the Elder, Galen, and Nicholas Culpepper.