Also, my friend who works at a pharma factory says brand names have much tighter quality control - more batches are tested with far less tolerance. In addition

Also, my friend who works at a pharma factory says brand names have much tighter quality control - more batches are tested with far less tolerance. In addition, some of the details of the chemicals (such as I guess the angles of the molecules) may be different, because the generic manufacturer imperfectly reverse engineers the process used to make the drug. Clinical trials to validate the generic are less strict.