The volatile oil also contains pulegone, a chemical also occurring in pennyroyal that is a known irritant, toxic to the liver, and also an abortifacient.
For groups that define pregnancy as beginning with fertilization, birth control methods that have postfertilization mechanisms are regarded as abortifacient.
In addition to citing the abortifacient nature of the drug, the letter cited reports of uterine rupture and death associated with using misoprostol to induce labor.
