Some people take Milk of Magnesia, which contains magnesium hydroxide, to alleviate constipation. While some studies find a benefit,[1][2][3][4] its overall efficacy is unclear due to a lack of high-quality research.[5][6] Other studies have found that magnesium oxide might also improve constipation;[7][8][9] similarly, however, further high-quality research is needed to draw firm conclusions concerning its efficacy.
It’s important to note that Milk of Magnesia has several drug interactions (e.g., aspirin, prednisone, cholecalciferol (vitamin D3)); therefore, people who use medications should consult their doctor before using Milk of Magnesia/magnesium hydroxide. Furthermore, Milk of Magnesia interacts with several conditions. People with intestinal disorders, kidney problems, or inflammatory bowel disease should also consult their doctor before using Milk of Magnesia/magnesium hydroxide.