Herbal product	Dosage	Use recommendation	Comments
Evening primrose oil24,25	500 mg per day to 1,000 mg three times per day	Days 17 through 28 of menstrual cycle	Most-studied of all herbs used in treatment of PMS
			May provide a precursor for prostaglandin synthesis
			Benefits breast tenderness
			Safety data in pregnancy and lactation lacking
			Not approved for this use by the FDA
Chaste tree berry24–26	30 to 40 mg per day	Days 17 through 28 of menstrual cycle	May benefit breast symptoms
			Inhibits prolactin production
			Safety data lacking
			Not approved for this use by the FDA