Information last reviewed: May 2026 — for educational purposes only.
What Is Seroquel (Quetiapine)?
Quetiapine, sold as Seroquel, is a second-generation (atypical) antipsychotic of the dibenzothiazepine class. It has a broad receptor-binding profile — blocking dopamine D2, serotonin 5-HT2A and 5-HT2C, histamine H1, and adrenergic alpha-1 and alpha-2 receptors. The combination of dopamine and serotonin antagonism accounts for its antipsychotic and mood-stabilising efficacy with low EPS risk. Its potent H1 antihistamine activity makes it highly sedating, which is exploited clinically for insomnia and agitation, but also contributes to daytime drowsiness and weight gain as side effects. Quetiapine is distinctive for its wide approved use spectrum — from schizophrenia to bipolar depression to MDD adjunct.
Prescription (Rx) Status
Quetiapine is prescription-only. Generic quetiapine IR and XR are widely available. Seroquel XR (extended-release) allows once-daily dosing. FDA black-box warnings: increased mortality in elderly dementia-related psychosis; suicidality in young patients when used as MDD adjunct. Notable off-label use for insomnia at low doses (25–50 mg) is widespread but debated due to metabolic and tardive dyskinesia risks even at low doses.
Uses of Quetiapine
FDA-approved: schizophrenia (adults and adolescents 13+), acute bipolar mania (monotherapy and adjunct), bipolar depression, bipolar maintenance (Seroquel XR), and MDD adjunct (Seroquel XR added to antidepressants). Off-label: insomnia, anxiety, PTSD-related nightmares, and delirium management.
Tablet Strengths
Quetiapine IR tablets: 25 mg, 50 mg, 100 mg, 200 mg, 300 mg, and 400 mg. XR tablets: 50 mg, 150 mg, 200 mg, 300 mg, 400 mg. Schizophrenia target dose: 300–800 mg/day. Bipolar depression: typically 300 mg/day at bedtime. MDD adjunct: 150–300 mg/day. For insomnia (off-label): 25–100 mg at bedtime. Always start low and titrate.
Price
Generic quetiapine IR is moderately priced (~$25–$60/month). Seroquel XR brand is expensive; generic XR is available and cheaper. Prices vary by strength and formulation.
Frequently Asked Questions
Q: Is Seroquel safe for sleep?
A: Low-dose quetiapine is widely prescribed off-label for insomnia due to its sedating H1 blockade, but carries metabolic risks, potential for tardive dyskinesia even at low doses with prolonged use, and sedation hangover. It is not FDA-approved for insomnia. Prescribers weigh benefits against risks individually.
Q: Does quetiapine cause significant weight gain?
A: Yes — weight gain is one of the most common side effects, particularly at higher doses. Metabolic monitoring for glucose, lipids, and weight is recommended regularly.
Q: How does Seroquel XR differ from regular Seroquel?
A: Seroquel XR releases quetiapine gradually over 24 hours, allowing once-daily dosing, reducing peak plasma concentration, and potentially improving tolerability (less sedation at peak).
Disclaimer: This page is for informational purposes only and does not constitute medical advice. Quetiapine requires a valid prescription. Always consult a qualified healthcare professional. See our full disclaimer.