Can Evening Primrose Oil Induce Labor?

Evening Primrose Oil (EPO) is thought to help soften or “ripen” the cervix for labor through the production of “prostaglandins”. While some small studies suggest that high doses of vaginal EPO might shorten the duration of early phase of labor and help with cervical ripening for someone having their first baby, there are no large studies to support that EPO decreases the length of active labor or that EPO will induce labor. 

While it is likely not harmful to use oral or vaginal EPO, it can be a messy process and to be effective you need to use more than one pill. Essentially, the research is just not strong enough to recommend EPO for cervical ripening or to induce labor. 

Originally wrote this for Pregnancy FAQs for Expectful.

Sources:

Diansuy, N. N. and Aguilar, A. S. (2017). The effectiveness of evening primrose oil gel capsule as a cervical ripening agent during labor induction as measured by bishop score on term singleton pregnant patients. Philippine Journal of Obstetrics and Gynecology. Volume 41(2), 1-4. T

Najafi, M., Loripoor, M., Saghafi, Z., et al. (2019). The effect of vaginal evening primrose on the Bishop score of term nulliparous women. NPT. 6(4), 202-211

Kalati, M., Kashanian, M., Jahdi, F., et al. (2018). Evening primrose oil and labour, is it effective? A randomised clinical trial. J Obstet Gynaecol. 38(4), 488 -492.