There's certainly a debate out there on that. I think consistency is key. If you switch from generic to name brand or vice versa, your doctor should monitor your symptoms and blood work to be sure that you are getting the right amount of hormone because you might process or absorb things differently. Another consideration with generic is when you refill your script at the pharmacy you may be getting a product that is made by a different company each time. The consistency of levothyroxine could vary.
I did fine on generic for many years, but recently my levels started jumping up and down. To be sure I was getting a product from the same company with more consistent potency in each tablet, I was switched to the name brand Synthroid.
According to the users review, generic synthroid is not as good as its brand name. This is because they differ in the amount of levothyroxine they contain and its distribution throughout the body. However, there are other patients who prefer using it. This would depend on the symptoms and the interactions it gives for everyone.