Many doctors feel that there IS a reason to stay brand specific wtih thyroid medications. Overall, ANY generic is the same as the brand name because fed law says they MUST be. BUT the rules say they must be within x amt more or less of the brand name drug. With a few medications, the difference can be enough to cause major problems. Specifically, thyroid and seizure medications are the ones I know of. If one medication is st the plus end of the acceptable spectrum and another is at the lowest end of the spectrum, you end up with more than the accepted difference.
To illustrate, the brand name is 10 units. Laws say generic must be plus or minus 1.5 units of the brand name. Generic A is at the low end, at 8.5. Generic B is at the high end, at 11.5. If your pharmacy gets different brands of generics (say Kroger brand instead of Great Value brand), you could go from Generic A's 8.5 to Generic B's 11.5 without knowing. That is a change of 3 units, not 1.5 and is still totally legal.
For most things this difference will NOT EVER be noticeable to you. Seizure medications can be noticeable and so can thyroid medications, or so the docs believe. Personally, what no one talks about is that from one batch to the next, ANY brand can vary a bit, and that is legal and also unavoidable.
How do you deal wtih this with-o spending a fortune on brand names that are not covered by insurance? Ask the pharmacy if they use the same generic supplier for their thyroid medications each time or if they get a different one each time. In my area, CVS uses the same generic brand for thyroid medications and has for four years now. Because of this, many people here go to them for thyroid medications.
To be honest, I have taken thyroid medications for years now. Past docs have not cared whether I use generic or not, or if the generic brand changes. For the most part, the gooddocs have judged whether I needed the medications adjusted by how I feel, not just what the tests say. I usually notice small changes, but I have yet to notice a difference from changes from one generic thyroid medication to another.
It is my understanding that if you are very sensitive to the thyroid medications, or you don't respond well to them, you may want/need to try a brand called Armour thyroid. It is supposed to be more natural, and some patients see a major difference between the synthetic thyroid medication and this natural one. It si the same medication, but the Armour brand is not synthetic, or comes from a more natural set of ingredients. Or that is what I have been told. I don't know for sure because I haven't needed to figure it out.
I hope this helps. In general, I would go with generic/store brand on EVERY medication whether it is OTC or brand name. The cost difference is often HUGE and the differences are too minor to be noticed by most people. If you do notice a difference that is a problem, explore the brand name but ONLY if you have problems. Why spend the $$ on brand name if you don't have to ?