List of products in the National Drug Code with proprietary name . Olanzapine injection is used to treat a certain mental/mood disorder (schizophrenia). Olanzapine helps you to think more clearly, feel less nervous, and take part in everyday life. It may also help to decrease hallucinations (hearing/seeing things that are not there). Extended-release olanzapine injection is a long-acting psychiatric medication called an atypical antipsychotic. It works by helping to restore the balance of certain natural substances in the brain. Talk to the doctor about the risks and benefits of treatment (especially when used in teenagers). See also Warning/Precautions sections.