How long will seroquel (quetiapine) stay in your system after stopping use?

Half-life important: Orally, seroquel (quetiapine) itself has a half-life of only 6 hours; half-life for its main by product is 12 hours if there's no liver or kidney disease. Without these, it should take about 60 hours for both the parent compound & active metabolite to be eliminated. If you're also on a medicine that slows the metabolism of seroquel (quetiapine) (like ketoconazole, etc) it would take longer.