Carbocalcitonin spray administered for 12 months at a daily dosage of 80 U MRC according to five schedules has been tested on 150 normal spontaneous postmenopausal women for its influence on bone mineral density (BMD), bone metabolism and osteoarticular pain. BMD was monitored before and at the end of treatment in comparison with BMD of untreated control women. Metabolic markers (serum alkaline phosphatase, serum osteocalcin and urinary hydroxyproline) were also evaluated before and during treatment (at the 9th or 10th month of treatment). Osteoarticular pain was assessed by an analogic visual scale. Intranasal carbocalcitonin, administered according to cyclic schedules at a high frequency dosage, was able to maintain bone mass only in the earlier postmenopausal women. BMD percent increase after 12 months of treatment was 1.10 and 1.31 in women with low (< 0.870 mg/cm2) and high baseline BMD (> or = 0.870 mg/cm2), respectively. In advanced menopause the maintaining effect of carbocalcitonin on BMD seemed evident only if the baseline bone mass was lower than the BMD of the age matched control group. At least six months of treatment/year is necessary for effective therapy. Both systemic and local tolerance were optimal. No significant side-effects were detected.