At a glance
Effects
- Sedation / somnolence: Drowsiness and sleepiness are among the most common effects, driven by histamine H1 blockade — this is also why it is misused as a sleep aid.[6][7]
- Calming / antipsychotic: Reduces positive and negative symptoms of psychosis and stabilises mood in bipolar disorder.[2][3]
- Antidepressant (adjunct): Used with antidepressants for major depressive disorder; the norquetiapine metabolite contributes to this effect.[1][6]
- No euphoria: Quetiapine has no euphoric effect of its own, but is misused to enhance or counter the effects of illicit drugs.[5]
Atypical (2nd-gen) antipsychotic
~6–7 h (parent quetiapine)
Oral (IR and extended-release tablets)
~1–2 h (immediate-release)
Prescription-only; not a controlled substance
Hepatic, mainly CYP3A4
About Quetiapine
Every point here is drawn from public medical and harm-reduction sources. A bracketed number after a claim — like [1]— is a reference: tap it to open the exact source it's based on (numbered list at the bottom). It is not a rating or score. Educational information, not medical advice.
Product specifics
- Est. delivery
- 3–7 business days · EU tracked
Product details as stated by the vendor (claims, not independently verified). Delivery is our standard EU estimate.
What it is
Quetiapine is an atypical (second-generation) antipsychotic used to manage schizophrenia, bipolar disorder (mania and bipolar depression) and, as an add-on, major depressive disorder.[1][3] It is widely (and increasingly) prescribed off-label at low doses, often for sleep or anxiety, despite guidance that low-dose off-label use is not recommended.[8][9]
How it works
Quetiapine works by changing the activity of natural signalling chemicals in the brain.[4] Its main antipsychotic effect comes from blocking serotonin 5-HT2 receptors, with weaker action at dopamine D1 and D2 receptors.[2] Its sedating and blood-pressure-lowering effects come largely from blocking histamine H1 and alpha-1 receptors, while an active metabolite (norquetiapine) acts as a norepinephrine reuptake inhibitor thought to contribute to its antidepressant effect.[6][7]
Risks & side effects
Most important: The single biggest concern for non-medical use is profound central-nervous-system depression: overdose can cause coma, dangerously low blood pressure, slowed breathing, seizures, QT prolongation and death, and the danger rises sharply when combined with alcohol, opioids or benzodiazepines.[10][11] It is the most-misused second-generation antipsychotic and combining it with other CNS depressants is especially hazardous.[12]
Common
Serious
- Metabolic changes: hyperglycaemia/new-onset diabetes, dyslipidaemia and weight gain; cases of fatal diabetic ketoacidosis have been reported.[4][16]
- QT-interval prolongation, with overdose risk of coma, hypotension, respiratory depression, seizure and death.[14][10]
- Neuroleptic malignant syndrome — a rare but potentially fatal reaction (fever, muscle rigidity, autonomic instability, raised creatine kinase).[17][2]
- Increased mortality and stroke risk in elderly patients with dementia-related psychosis (boxed warning).[18][1]
- Increased risk of suicidal thoughts and behaviour in children, adolescents and young adults (boxed warning).[18]
Safety & harm reduction
- Elderly patients with dementia-related psychosis — increased risk of death and stroke; not approved for this use.[18][1]
- Children under 10 years of age — not approved.[18]
- Caution/avoid in people with risk factors for QT prolongation (heart disease, electrolyte abnormalities, congenital long QT, other QT-prolonging drugs).[14]
- StatPearls notes there are currently no absolute FDA contraindications, but the boxed-warning populations above should not use it.[2]
- Baseline and regular weight/BMI, waist circumference, blood pressure, fasting glucose and lipid profile.[4][16]
- ECG and potassium in those at risk of QT prolongation, after starting and with dose/risk changes.[14]
- Watch for emergence of suicidal thoughts, especially in young people.[18]
- Periodic lens (eye) examination during long-term treatment.[20]
- Thyroid and metabolic parameters, as quetiapine can affect thyroid function in susceptible people.[3]
- Strong CYP3A4 inhibitors/inducers alter quetiapine levels; after stopping a strong inducer, the dose may need a 5-fold reduction within 7–14 days.[10]
- Other CNS depressants (alcohol, opioids, benzodiazepines, sodium oxybate) — additive sedation, respiratory depression, coma and death.[12][14]
- Serotonergic/dopaminergic agents — risk of serotonin syndrome or neuroleptic malignant syndrome.[14][17]
- Other QT-prolonging drugs increase arrhythmia risk.[14]
- Use the lowest effective dose for the shortest necessary time, particularly for off-label/low-dose use.[13]
- Taper gradually under medical supervision rather than stopping abruptly to avoid withdrawal.[19]
- Never combine with alcohol or other sedatives recreationally; overdose can require intensive resuscitation.[12][10]
- Seek emergency care for signs of NMS (high fever, rigidity, confusion) or severe overdose.[17][10]
Dosage context
Commonly-reported, not a prescription: licensed daily doses range up to about 800 mg for schizophrenia and bipolar disorder and up to ~300 mg as an adjunct for depression.[10] Off-label low doses (<150 mg/day) are increasingly prescribed for sleep/anxiety but are explicitly not recommended, and even low doses cause measurable metabolic harm (≥7% weight gain roughly twice as likely vs placebo).[8][13] Maximum effective dose for the lowest necessary duration is advised; abrupt stopping should be avoided.[13][19] These figures are context only, not dosing advice.
Sources
- 1.DrugBank — Quetiapine
- 2.StatPearls (NCBI Bookshelf) — Quetiapine
- 3.Reversible Thyroid Dysfunction Associated With Quetiapine (PMC)
- 4.FDA label — Quetiapine fumarate ER (accessdata.fda.gov)
- 5.Cleveland Clinic Journal of Medicine — Quetiapine for primary insomnia
- 6.MedlinePlus — Quetiapine
- 7.Divergent effects of quetiapine on dopamine neuron activity (PMC)
- 8.Metabolic Adverse Effects of Low-Dose Quetiapine (PubMed)
- 9.Overdose of Quetiapine — A Case Report (PMC)
- 10.Can you overdose on Seroquel? (Drugs.com)
- 11.DailyMed — Quetiapine fumarate tablet
- 12.A Brief Review of Quetiapine (AJP Residents' Journal)
- 13.Effect of Quetiapine on Weight and Metabolic Traits (PubMed)
- 14.DailyMed — Quetiapine fumarate tablet, film coated (adverse reactions, QT)
- 15.SingleCare — Seroquel side effects and half-life
- 16.Quetiapine-Induced Hyperglycemic Crisis & Hyperlipidemia (ScienceDirect)
- 17.NMS following antipsychotic switch to quetiapine (PMC)
- 18.DailyMed — Quetiapine fumarate tablet (boxed warnings)
- 19.Quetiapine Side Effects, Misuse, and Withdrawal (Recovered.org)
- 20.FDA label — Quetiapine (NMS, tardive dyskinesia, cataracts)
This information is provided for educational and harm-reduction purposes only. It is not medical advice. These substances can carry serious health risks; effects and safe use vary by individual. Consult a qualified healthcare professional before use. Legal status varies by country — it is your responsibility to know your local law. We do not encourage misuse.
Substance reviews(8)
Independent reviews of this compound from the wider market — about the substance, not our delivery. Showing the 2 with written feedback.
- ★★★★★1 month ago
Costs a bit more but totally worth.
- ★★★★★1 month ago
From the moment it arrived safely packed and right on time I knew I d gotten a great deal.