One type of magnesium, magnesium hydroxide, was used in a 2005 study in BJOG to see how it affected women’s issues with an overactive bladder and frequent urges to pee. Forty women were either assigned to take magnesium hydroxide or a placebo. More than half of the women taking magnesium said their urinary symptoms improved and they didn’t have side effects. However, 1 in 5 of the women in the placebo group also said their symptoms improved. Additionally, the researchers didn’t find any significant changes to their bladder function.
If you want to take a magnesium supplement to see if it reduces your nighttime bathroom trips, magnesium hydroxide is typically used to treat constipation. You’ll find this form of magnesium in Milk of Magnesia or Pedia-Lax. Magnesium glycinate, magnesium malate, and magnesium citrate are more easily absorbed by your body, but no research supports their effect on urinary conditions.