@drsuefowler it's interesting that your endo has a clinical observation on the differences of side effects for these two anabolics. I've read some publications on various dosing of Forteo. The 20mcg and 40mcg of Forteo were compared in a randomized clinical study. The 40mcg Forteo increased bmd more than 20mcg, however, the 2 doses had similar effects on the risk reduction of fracture. 40mcg seemed more likely to cause side effects. These might be the reasons that 20mcg was marketed. A dose of 56.5mcg once weekly is used in Japan. In their clinical study, the dropout rate for this dose, even once weekly, is high compared to placebo group due to side effects.

Although we can't compare side effects directly between Tymlos vs Forteo, a dose-dependent relationship for side effects may exist. If you are stabalized with 40mcg Tymlos, you might want to titrate upwards like @windyshores suggested to see if tolerable. Thank goodness the pen is adjustable. Otherwise, your endo may have a point.

I took Forteo also with minimum side effect - only fatigue due to low blood pressure for first one and a half months, nothing else. Increased hydration and salty food/liquid helped a lot. Sometime I wonder if the side effects of these two meds are more noticable to those of us who have low blood pressure to start with.