In Brief Menstrual cramps are caused by prostaglandins; lowering them reduces pain. Dietary changes (Omega-3s, Magnesium) should start 7–10 days before your period. Heat therapy and hydration are proactive tools, not just reactive fixes. Timing OTC medication before pain starts is more effective than waiting. If you are a woman who menstruates, you likely know the feeling all too well. It begins as a dull, heavy ache in the lower abdomen, perhaps radiating to the lower back or even the thighs. For some, it is a minor annoyance, a background noise to the day. For others, it is a m…