What is the safest osteoporosis medicine?

Although some firstline meds for osteoporosis have fallen out of favor with some clinicians, bisphisphonates like fosamax or actonel are still felt to be useful& effective in preventing fractures but only in people who are at high risk for fractures like those with significant osteoporosis or are on chronic corticosteroid meds. However most MD's are limiting them to a 5 year course. Talk with MD