Lanthanum carbonate hydrate LaCO₃OH/La₂ (CO₃)₃-xH₂O

Which has been used to treat  and hyperphosphatemia in patients with renal failure, is a molecule which is prone to decarboxylation under certain stressful conditions such as high heat and elevated humidity. These conditions may be present during the manufacture of lanthanum carbonate hydrate or during the storage of the unformulated or formulated material. The decarboxylation product is lanthanum hydroxycarbonate.

Lanthanum, like the other lanthanides, is known to affect human metabolism, lowering cholesterollevels, blood pressure, appetite, and risk of blood coagulation. When injected into the brain, it acts as apainkiller, similarly to morphine and other opiates, though the mechanism behind this is still unknown.