@awfultruth thank you so much for your link! A great comprehensive review and explanation of increased porosity, cortical thickness, and outer diameters of cortical bone resulted from Teriparatide treatment. The increase porosity that concern some of us doesn’t appear to be correlated with bone strength reduction. Rather, it is accompanied by apposition of new bone at peristeal site etc. As @gently pointed out, coupled bone remodeling is crucial for healthier and stronger bones. The porosity increase may just provide more grounds for the coupled process. Bone strength is multi factorial based. Anatomical and mechanical properties play important role, other than bmd. This paper explained how the outer diameters’ increase actually plays a role in resistance to fracture.

Thank you @awfultruth and @gently! I leant a lot from your perspective and help.