Ferric Ammonium Citrate

Ferric Ammonium Citrate (FAC) is a highly water-soluble, complex green or brown powder/granule () used primarily to treat iron-deficiency anemia. It serves as an iron supplement (providing 16.5–18.5% elemental iron), food additive, and in photography (blueprints). Common side effects include nausea, constipation, and dark stools. Medical and Pharmaceutical Uses Iron Deficiency Treatment: It is a key ingredient in hematinic supplements used to treat and prevent iron-deficiency anemia. It is often preferred in liquid formulations because of its excellent solubility. MRI Contrast Agent: In medical imaging, it is used as an oral paramagnetic contrast medium to improve the quality of magnetic resonance imaging (MRI) for the digestive tract. Gentle Digestion: Compared to other iron salts like ferrous sulfate, it is often noted for being gentle on the digestive system with higher bioavailability and reduced irritation. Food and Industrial Applications Food Fortification: It is added as an iron fortifier to various products, including infant formula, cereals, dairy products, and wheat flour. Beverage Ingredient: It serves as an acidity regulator (INS 381) and is famously used in the Scottish soft drink Irn-Bru. Photography: It is a critical component in the cyanotype photographic process (blueprint printing), where it reacts with light to create a blue pigment. Water Treatment: It can act as a coagulant to help remove impurities and organic loads during water purification. Potential Side Effects Common Reactions: Similar to most iron supplements, it may cause stomach upset, nausea, constipation, or diarrhea. Stool Discoloration: It frequently causes black or grayish stools, which is a harmless result of unabsorbed iron. Oral Discoloration: Tablets or liquids can cause temporary teeth or mouth staining if they are chewed or held in the mouth too long.