Prolia is a RANK ligand (RANKL) inhibitor with a number of indications. Prolia contains denosumab as its active ingredient. Denosumab is a human monoclonal antibody that is specific to the human receptor activator of nuclear factor kappa-B ligand (RANKL). Prolia works by blocking RANKL from binding to its receptor on osteoclasts. RANKL is a protein that is essential to the development and survival of osteoclasts, which are cells that contribute to bone resorption. By preventing osteoclast formation, bone resorption is decreased, which in turn helps reestablish a healthy bone remodeling rate.