Seroquel XL is a brand name for the extended-release formulation of quetiapine, an atypical antipsychotic medication primarily used in the treatment of certain mental health conditions such as schizophrenia, bipolar disorder, and major depressive disorder in adults. It works by altering the actions of chemicals in the brain, helping to restore the balance of neurotransmitters. The "XL" in its name indicates that it is an extended-release version, designed to be taken once daily, allowing for more consistent levels of the medication in the bloodstream over a 24-hour period. This can help improve compliance and decrease the likelihood of side effects associated with peak doses. Like all medications, it can have side effects and is prescribed by a healthcare provider based on an individual's specific condition and response to treatment.