Meanwhile, cathepsin K (CTSK) positive osteoclasts were increased in OVX mice than sham group but there was no significant difference on the expression of CTSK with FSK treatment in the bone marrow of OVX mice (Figure S9D, Supporting Information), which demonstrated that osteoblasts but not osteoclasts were responsible for the anti‐osteoporosis effect of FSK. This evidence concerns the gene CTSK and osteoporosis.