Zyprexa, generically known as olanzapine, is an atypical antipsychotic medication primarily used to treat schizophrenia and Bipolar disorder. It works by affecting neurotransmitters in the brain, particularly serotonin and dopamine. Zyprexa can help alleviate symptoms such as hallucinations, mood swings, and agitation. Common side effects may include weight gain, drowsiness, and metabolic changes.