Derived from the castor plant Ricinus communis, castor oil may possess properties that are useful in post-term pregnancies Research studies reveal that castor oil was considered successful if labor began within 24 hours after dosing. Women who receive castor oil have an increased likelihood of initiation of labor within 24 hours compared to women who receive no treatment. Castor oil use in pregnancy is underreported worldwide. Read More: http://www.ncbi.nlm.nih.gov/pubmed/10631825