A pill containing a mix of essential oils has been shown to significantly reduce the symptoms of premenstrual syndrome¹ (PMS月经前不快症状). Researchers writing in BioMed Central's open access journal Reproductive Health tested the tablets by carrying out a randomised, controlled trial in 120 women. Edilberto Rocha Filho worked with a team of researchers from the Federal University of Pernambuco, Brazil, to conduct the tests. He said, "The administration of 1 or 2 grams of essential fatty acids to patients with PMS resulted in a significant decrease in symptom scores. Furthermore, the administration of the dietary supplement did not result in any changes in the total cholesterol²（胆固醇） in the patients evaluated".

Women who were given capsules containing 2 grams of a combination of gamma linolenic acid（亚麻酸） , oleic acid（油酸） , linoleic acid（亚油酸） , other polyunsaturated acids（多不饱和酸） and vitamin E reported significantly eased PMS symptoms at both 3 and 6 months after they began the treatment. Few adverse³ events were recorded and these were mild, insignificant⁴ and did not appear to be directly related to the medication. Speaking about the results, Rocha Filho said, "The negative effect of PMS on a woman's routine activities and quality of life may be significant, in addition to the repercussions⁵（反响，影响） on economic costs resulting predominantly from a reduction in productivity. Essential oil capsules can now be said to show much promise as a treatment".