From the #1 Milk of Magnesia Brand, Phillips’ Milk of Magnesia Fresh Mint Flavor Liquid Laxative is a saline laxative that provides gentle overnight relief of occasional constipation. Formulated with Magnesium Hydroxide, Phillips’ Milk of Magnesia provides cramp and stimulant free relief of occasional constipation. (The product usually produces a bowel movement in 30 minutes to 6 hours). This milk of magnesia liquid laxative works with the body’s natural process to relieve occasional constipation.