Rose,
Tymlos immediately activates the receptor in the distal renal tubules which stimulates G-alpha-s proteins. This triggers adenylyl cyclase which increases intracellular cAMP production. The cAMP pathway move calcium back into the bloodstream contributing to the initial peak calcium concentration. It is the high concentration of calcium that relaxes the blood vessels.
Tymlos doesn't bind and isn't soaked up by the bone. It interacts with a hormone receptor on a cell called an osteoblast stimulating that cell to manufacture and secrete a soft matrix called osteoid. The osteoblast isn't actually bone.
Kidney size and mass is one factor in the body's resulting total fluid volume. Bladder capacity affects the level of total blood volume and extracellular fluid volume.
But none of this proves that 80mcg of abaloparatide is too high a dose for some of us lightweights. Nor do your views expressed expressed above prove that 80mcg is the perfect dose without regard to weight.
If someone were allergic to the preservative in Tymlos there is no doubt that lower body weight would be increase the negative effect of the 2mcg of phenol in a Tymlos dose.