Apiole is a phenylpropene, also known as apiol, parsley apiol or parsley camphor. Its chemical name is 1-allyl-2,5-dimethoxy-3,4-methylenedioxybenzene. It is found in the essential oils of celery leaf and all parts of parsley. Heinrich Christoph Link, an apothecary in Leipzig, discovered the substance in 1715 as greenish crystals reduced by steam from oil of parsley. In 1855 Joret and Homolle discovered that apiol was an effective treatment of amenorrea or lack of menstruation.
In medicine it has been used, as essential oil or in purified form, for the treatment of menstrual disorders and as an abortifacient. It is an irritant and, in high doses, it can cause liver and kidney damage. Cases of death due to attempted abortion using apiol have been reported.
Hippocrates wrote about parsley as a herb to cause an abortion. Plants containing apiole were used by women in the Middle Ages to terminate pregnancies. Now that safer methods of abortion are available, apiol is almost forgotten.