Apparently it is down to an enzyme called bromelain which can aid in muscle relaxation - well so the internet tells me, lol. My eldest daughter told me about it a couple of years ago and it works for all the women in the house. My husband was very relieved and kept us stocked up. I hope it works for you. Periods are evil. Someone should have invented a button (just by the elbow maybe?) to switch them on and off by now. I know what you mean about there seeming to be less risks with herbal stuff. My daughter had full on hallucinations from taking dental medication one time. Not sure how anyone could get addicted to that but apparently you can.