Evening Primrose Oil

    Written by:
    Katie Jantz

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    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.

    41 references on this page
    4,844 participants in trials and 6 meta-analyses

    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]

    Examine Database: Evening Primrose Oil

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    Examine Database References

    1. Eczema Symptoms - Bamford JT, Ray S, Musekiwa A, van Gool C, Humphreys R, Ernst EOral evening primrose oil and borage oil for eczema.Cochrane Database Syst Rev.(2013-Apr-30)
    2. Labor Duration (Pregnancy) - Shahinfar S, Abedi P, Jahanfar S, Khajehpoor M, Chashmyazdan MThe effect of evening primrose oil on cervical ripening and birth outcomes: A systematic review and meta-analysis.Heliyon.(2023 Feb 8)
    3. Labor Duration (Pregnancy) - Hemmatzadeh S, Mohammad Alizadeh Charandabi S, Veisy A, Mirghafourvand MEvening primrose oil for cervical ripening in term pregnancies: a systematic review and meta-analysis.J Complement Integr Med.(2023-Jun-01)
    4. Total cholesterol - Khorshidi M, Zarezadeh M, Moradi Moghaddam O, Emami MR, Kord-Varkaneh H, Mousavi SM, Alizadeh S, Heshmati J, Olang B, Aryaeian NEffect of evening primrose oil supplementation on lipid profile: A systematic review and meta-analysis of randomized clinical trials.Phytother Res.(2020-Oct)
    5. Breast Tenderness - Ahmad Adni LL, Norhayati MN, Mohd Rosli RR, Muhammad JA Systematic Review and Meta-Analysis of the Efficacy of Evening Primrose Oil for Mastalgia Treatment.Int J Environ Res Public Health.(2021-Jun-10)