What causes period pain? How do these herbs help with that?

During menstruation, your uterus contracts to expel its lining. Hormone-like substances known as prostaglandins trigger the uterine muscle contractions. Higher levels of prostaglandins are associated with pain, inflammation, and more severe menstrual cramps. To get at the root of the problem, these herbs act to regulate the levels of prostaglandins and other cycle-related hormones. They also treat painful symptoms by relaxing the uterine muscles, reducing pain, and regulating your cycle.