This was a randomized, double-blind, double-dummy, multiple dose, placebo-controlled, parallel group, 48- week, Phase III study. Women age 45 and over who were postmenopausal and had a diagnosis of osteoporosis were eligible for the study and were randomly allocated to one of three treatment groups; placebo tablets, oral rsCT tablets or calcitonin nasal spray. Each patient was given a treatment kit, which contained the study medication to which she had been assigned and a placebo of the treatment to which she was not assigned, or placebo nasal and oral preparations, as well as the required dietary supplements (calcium and vitamin D tablets). The study medication and supplements were self-administered at home. It was anticipated that approximately 545 patients would participate in the study.