Hi Energizer Bunny:  There are two schools of thought on this question.  Some Drs believe you shouldn't take anything else (bone meds) with Forteo, and then if you read the Cleveland Clinics pdf on Forteo, they say that HRT may not affect the results of the Forteo.  I would ask your Dr and see what they say.  My Dr claims that theorectical hormones should affect the response but who's to say if she knows for sure.  Hormones are an antiresorptive *similar* to bisphosphonates so you and your Dr will have to decide.

I took HRT, not bioidentical hormones for 6 mos while on Forteo, and my bone marker test did go down, which you wouldn't expect to happen while on Forteo unless it wasn't working properly, or I was loosing more bone. 

Here's a link on the response in markers while on Forteo and Antiresorptives from Medscape.  Hopefully this will explain this a bit further--you have to register to read this but it's free and simple. 

Forteo and Other meds. 

Good Luck...