The efficacy and safety of ipriflavone, a new anti-osteoporotic agent, has been evaluated in an open study in 100 agent, has been evaluated in an open study in 100 osteoporotic women. Ipriflavone was administered as oral capsules dosed at 200 mg, 3 times a day for 12 months. Ninety women completed the study, and the results indicate that the bone mineral density was increased by 2% and 5.8% after 6 and 12 months, respectively. Pain and rachis mobility seemed to be positively influenced by ipriflavone. Only three women complained of side-effects (gastralgia and nausea) and asked to stop the therapy.