Background <p>Our research aims to explore the effect of salmon calcitonin (sCT) combined with three calcium antagonists (CCA), verapamil, nifedipine and diltiazem, on calcium and phosphorus ion metabolism in the blood of osteoporotic female rats following ovarian removal. To explore a method of combination medication suitable for postmenopausal women with osteoporosis.</p> Methods <p>We first carried out the combined drug experiment on rats, and then carried out the combined drug experiment on osteoporosis rats. Blood samples were collected at 1, 2, 4, 8 and 12&#xa0;h post-administration, and then we measured the concentration of calcium and phosphorus ions in serum.</p> Results <p>Osteoporotic rats were divided into eight groups, with 6 rats in each group, with an average weight of 350&#xa0;g. By studying changes in the concentration of calcium and phosphorus ions in the blood over a period of time, we found that the effect of sCT combined with nifedipine and verapamil in reducing serum calcium and phosphorus was better than that of single drug; the effect of sCT combined with diltiazem in reducing serum calcium was better than that of single drug, and the effect of reducing blood phosphorus was not as good as that of single drug.</p> Conclusions <p>We have studied and found that the group of sCT combined with nifedipine group has the most significant effect on reducing calcium and phosphorus in the blood of osteoporotic rats. The effect was significantly better than salmon calcitonin alone. That provided a new medication method for postmenopausal women with osteoporosis.</p> <p>Clinical trial number.</p> <p>Not applicable.</p>