Bobbi
Just to add something to Ski’s last point, this summer my local pharmacist "goofed’"- TWICE- and gave me generic replacement hormone instead of the brand name that my endo insists on. It becomes automatic if they are not careful, because insurance companies generally demand that we use generic. NEvertheless, because I had difficulty getting regulated, I insist upon being given a brand.
If you shift from one brand to another, your endo would have you come in about 6 weeks – 3 months after the switch to make sure that the dose you are on is appropriate. But your pharmacy could buy different "brands" of generic medication, so you might be switched without knowing it if you are on the generic. That, at least, is the rationale for insisting on a "brand" as far as I know.
Bobbi – Online Facilitator