@neverretire I do not know the standard length of time. Or if there is a standard time. My friend in her 80's is taking Prolia for the rest of her life.

A poster in another forum said her doctor said 5 years. I have seen studies for 3, 4 and 8 years.

McCormick writes that studies showed that Reclast given 6 months after Prolia preserved bone density for at least two years. "However another study of women who had been on denosumab for seven years found that even with zolendrate as sequential therapy, they still suffered a substantial loss of bone. Even multiple zoledronic acid infusions may not be enough to stop the rebound if denosumab therapy is discontinued after it has been used long term." (pages 548-9

That said a chart in Great Bones shows that Prolia can bring 6-8% improvement in spine bone density in two years (Reclast brings 3-4%). Hip is at 2-3 % for all anti-resorptives including these two.

McCormick suggests doing 1-3 injections to get that benefit, if Prolia is the chosen drug, and stopping at that point so that the rebound can be handled well with Reclast. He suggests using the bone marker CTX, which measures the bone turnover rate, to decide when to do the Reclast, but other providers say to just do the Reclast at 6 months.

McCormick is just one expert, very well-versed, not a physician but a chiropractor who has dedicated himself to osteoporosis. Dr. Ben Leder , and endocrinologist at MGH, has similar info.

I know it seems like this puts you between a rock and a hard place but there is a solution and a good endo can help you find it. I am hoping that research will quickly show that Evenity is an option for those leaving Prolia, either after Prolia or after Reclast.