Hello HealthyAnnie. Magnesium would not make a good long term supplement for headaches, since Magnesium when used in certain instances for example when combined with calcium supplements for a period of time may cause depression from a drop in seratonin levels. That is one of the things I have tried and have felt the side effects from by not being educated enough to self medicate appropriately. If you are having headaches I would suggest seeing a medical Dr to help explain the reason for the headaches rather that just medicating or using medication in order to control the headaches. Sinus and other reasons may be responsible for your headaches, and you would be better off getting a diagnosed from a professional than self medicating for a long term period for something you have not been diagnosed to treat. It is always better to err on the side of safety where health is concerned I feel especially for women. Take care and good day. Phoelona