Samidorphan is an opioid antagonist. Samidorphan supposedly reduces weight gain that very frequently occurs with olanzapine. ALKERMES INC, a pharmaceutical corporation, concluded that individuals with schizophrenia could benefit from less than normal opioid agonism, which fits right in with the history of the treatment of schizophrenia. Some terrible treatment is somehow or other a boon to individuals with schizophrenia. Olanzapine/samidorphan, with olanzapine being the antipsychotic and samidorphan being the opioid antagonist, combines two pleasure killing drugs in one pill so, of course, olanzapine/samidorphan is a treatment advance for individuals with schizophrenia. Metabolic parameters did not vary between olanzapine and olanzapine/samidorphan and individuals on olanzapine/samidorphan still gain weight. Also a meta-analysis indicates that olanzapine/samidorphan is not effective in reducing weight gain due to olanzapine. LYBALVI, an olanzapine/samidorphan combination, was recently approved by the FDA for the treatment of schizophrenia and bipolar 1 disorder.