@singingbones
Just to clarify my earlier comment about aiming for the lower half of the healthy premenopausal CTX range: this isn’t a standard recommendation or a validated target. It’s an empirical approach some doctors use to gauge antiresorptive effect. The bone specialist I spoke with happens to be one of them.

Unlike bisphosphonates, estrogen comes in many doses (and formulations), and its dose-response with BTMs is less well studied. That said, a few publications (including an ASBMR Task Force report) describe experts using the premenopausal range as a practical signal, for example, restarting treatment of bisphosphonates after a holiday when markers rise above the lower half. The Endocrine Society, on the other hand, stresses that there’s real uncertainty about what an “optimal” BTM response even is, and that serial measurements need the same assay and must exceed the least significant change (around 56% for CTX in their example).

In my case, my doctors had planned to bump the estradiol patch from 25 to 50mcg. The specialist suggested looking for CTX in the lower half of the premenopausal range, but my response to 25 mcg was already very strong, so I was instructed to keep using the same low dose.

So my point wasn’t that guidelines say estrogen dose should be titrated to a specific CTX level - just that some docs use this range empirically, and that’s what happened in my situation. And of course, always best to follow your own physicians, who know your full clinical picture.