I took strontium for two years. Then stopped for 9 months. Had a dexa that showed I no longer had osteoporosis. I went from a -3 in the lumber spine to -2.2. But I have to say I exercise quite alot. I bought a pedometer, and started slowly from 2,ooo steps at least three times a week to 10,ooo steps 3x week. I also walk everywhere, and always take the stairs, rather than elevators. I probably do at least 24 miles of aerobic walking every week. I have gone back on strontium. I have never had any side effects from it. Also I have added light weights to my workouts. I just can't really say if it was the strontium, or the exercising that gave me the 10.6 increase in bone mass. Also I am post menopausal. Everywhere I turned they said because I was post menopausal it couldn't be reversed with exercise. Not true, obviously. Although it could be the strontium.