Properties: In the stomach, it acts as a local antacid, neutralizing hydrochloric acid. Its effects are slow but prolonged and, as it is not a very strong alkalizing agent, there are no risks of alkalosis, nor is it a mild laxative. hinders proteolytic digestion. In the intestine, and in sufficient quantities, it acts as a mild laxative, by osmosis. It usually takes effect 4-12 hours after ingestion, without causing colic or irritation. As a supply of magnesium, mainly for the bones. Composition: