FYI, I ended Tymlos in January and have been on alendronate for four months. I just had my P1NP tested; it dropped 50 percent. My understanding is that this is normal and expected, since alendronate slows down the bone remodeling process. Think about how much P1NP jumped when you were taking an anabolic. Well, it goes back down after you're done.

My CTX also fell, but not as much; I think as long as CTX stays at a reasonably low level, you're good. The ratio of the two, that many people track, is apparently not useful when you're on an anti-resorptive. I'm mostly interested in what the next DEXA says at year-end.