Evening Primrose Oil 1000 mg: PMS and Hormone Balance Nature''S Bounty Evening Primrose Oil 1000mg 60softgels, Non NOW Evening Primrose Oil 1000 mg 90 Veggie Softgels Hale and Evening Primrose Oil 1000 mg: PMS and Hormone Balance. Evening Primrose Oil 1000 mg 90 Pinnac Rich in essential fatty acids. Evening primrose oil has been studied to treat conditions related to menstruation and menopause. These conditions include cyclical breast pain, premenstrual syndrome (PMS), hot flashes, and osteoporosis. It has also been studied to treat skin and inflammatory conditions.