How long Seroquel stays in your system depends on factors like the dose and your overall health, but its noticeable effects usually last about 7 hours or longer. On average, the amount of Seroquel (quetiapine) in your body decreases by half about every 7 hours.
Although Seroquel may cause drowsiness, it is not usually prescribed only to help with sleep. When you first start treatment, it may take 1 to 2 weeks before you notice improvement in the condition it was prescribed to treat.
Factors like age, liver function, and dosage can influence how long Seroquel stays in your system and how it affects you. For this reason, it is important to take it exactly as prescribed and not change the dose on your own.
If you have questions about Seroquel, including how long it stays in your system, it’s best to talk to a psychiatrist, neurologist, or primary care provider.