18 mg Elemental Iron in Gastric Protection Complex Gentle, Non-constipating Supports Oxygen Transport Dietary Supplement VegetarianIronSorb contains Iron Protein Succinylate (IPS), an iron complex that is specially prepared to reduce irritation of the stomach in comparison to other forms of iron. IPS is gentle to the stomach because it dissolves in the intestine. Iron is an essential trace mineral required as a component of hemoglobin and myoglobin for transport of oxygen to tissues. Supplemental iron is essential during pregnancy and for many teenage males and females.