Evening Primrose Oil

    Written by:
    Katie Jantz

    Fact-checked

    by:

    Nick Milazzo, Natalka Roshak
    Last Updated: November 30, 2023

    Evening primrose oil (EPO) is extracted from the seeds of the evening primrose plant and is primarily composed of the omega-6 fatty acids linoleic acid and gamma-linolenic acid. EPO may improve cervical readiness during childbirth, but most clinical trials have been small and there are safety concerns that must be considered.

    Overview

    Dosage information

    EPO is available in both liquid and capsule form. In clinical trials, oral EPO dosages have generally ranged from 500 mg up to 6 grams daily. For cervical ripening, EPO capsules inserted vaginally appear to be most effective, and dosages of 1 to 4 grams daily are often used. Importantly, optimal dosing of EPO has not been established.[1][2]

    The composition of EPO will vary depending on the growing environment and extraction methods used, which could result in varying effects of EPO depending on the preparation used. EPO is also prone to oxidation and should ideally be stored in a dark and tightly sealed container.[2]

    Frequently asked questions

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