Both of the truely fine endocrinologists consulting with me recommend Reclast after Forteo.

With the removal of the black box warning on Forteo the future for those of us long lived with osteoporosis has changed. Not only can you repeat Forteo after using an interlude drug, but the response to a second two years on Forteo is as robust as the first.

Aftermarket clinical studies have proven that the 18 month limit on Forteo and Tymlos is unnecessary. Neither drug causes or is associated with an increase in bone cancer.
https://www.ccjm.org/content/88/9/489