It is an ore of lanthanum metal (bastnäsite), along with monazite.

It is prescribed for the treatment of hyperphosphatemia, primarily in patients with chronic kidney disease.

For cats with hyperphosphatemia it is available under the trade name Renalzin by Bayer Animal Health.

[2] However, when lanthanum carbonate is used for treating hyperphosphatemia, its side effects, namely myalgia, muscular cramping, and peripheral edema, should be clinically monitored.

[3] Lanthanum carbonate is also used for the tinting of glass,[citation needed] for water treatment, and as a catalyst for hydrocarbon cracking.