If by bad you mean has a lot of side effects yeah it’s bad, but spoiler alert every AP has a lot of side effects. Aside from side effects it is supposed to be one of the more effective meds.
Meds are separated into 3 classes the Rips&Pips, the dones and the pines (those just refer to the ends of the names of the meds). In order of strength from least to strongest you have Rips&Pips<dones<pines, in order of least side effects to most side effects you have the same order Rips&Pips<dones<pines. Now that’s not going to be everyone’s experience but that’s the general conclusion psychologists have come to. So zyprexa is one of the stronger APs but as a consequence to that, more side effects. It’s especially known for weight gain and is the most likely to cause it along with clozapine.