Used in medicine as a phosphate binder for patients with chronic kidney disease. It helps reduce phosphate levels in the blood by binding to dietary phosphate in the gastrointestinal tract, preventing its absorption. This action supports the management of hyperphosphatemia, a common complication in dialysis patients. The compound releases lanthanum ions in the gut, which form insoluble complexes with phosphate that are excreted in feces. It is taken orally, usually with meals, and is valued for its effectiveness and relatively low risk of aluminum-like toxicity.