The 8PG (10−6 M) was more potent in inhibiting osteoclastogenesis than genistein (10−5 M) and it down-regulated NFATC1, cSRC, MMP-9 and Cathepsin K. It was concluded that 8-prenyl plays an important role in influencing the osteoclast activity and intestinal biotransformation of 8PG, which provides evidence supporting the further development of 8PG as a good anti-osteoporosis agent. This evidence concerns the gene CTSK and osteoporosis.