I've been on Forteo for 10 months without any noticeable side effects. While I measured the blood pressure drop, I never felt dizzy. I hydrate before the injection and have something salty to ear or drink to mitigate the vasodilation that causes low blood pressure. Onset of dilation commences within minutes of the injection. The endocrinologist I see says that vasodilation is what causes headaches in some. The effect diminishes over the next two to four hours.
Some people do have unfortunate side effects. The nice thing about Forteo is that you can simply stop taking the drug. It doesn't linger in your system.
Some with side effects tolerate those effects and find the gains worthwhile. I'd advise anyone against tolerating side effects because there are alternative medications.
I wish you the luck. I think Forteo is the best drug.