Hi @tkdesign, Clinical studies in the past had shown that without an antiresorptive to follow Forteo treatment, the bmd gained from it were mostly lost in 1-2 years. On average, women lost at a faster rate than men did. If someone has uncontrolled secondary cause(s) of osteoporosis, the loss might be faster. There was a link/graph posted by @gently a few days ago that shows rate of bone loss after cessation of various osteodrugs.

One can certainly use HRT or SERM (Selective Estrogen Receptor Modulator) as an antiresorptive after an anabolic. The question then becomes whether or not their effects are adequate, and what's the optimal duration of their use. I think we have some members here used raloxifene (Evista) after Forteo for maintenance. @teb on this forum has been using HRT x6-7 years since finishing Forteo treatment.