How Long Does Seroquel Stay in Your System?

So, you are wondering how long does seroquel stay in your system? To understand that, you ought to understand how the drug seroquel works and its content. Seroquel is a brand name of quetiapine. A medication often prescribed to treat people with schizophrenia and other similar psychotic conditions like bipolar and depression.

However, people without any of these conditions may feel the need to abuse it because of the effect the drug has on them. 

Table of Contents

★ Mechanism of action of seroquel 

★ The side effects 

★ How to take seroquel 

★ How long seroquel stays in your body    

★ Factors that influence the half-life of seroquel


Quetiapine fumerate is the active ingredient contained in seroquel, it belongs to a family of drugs known as antipsychotics. Quetiapine fumerate changes the levels of dopamine and serotonin, two neurotransmitters found in the brain that are responsible for regulating mood and the brain reward system. 

When this drug is introduced into the bloodstream, you tend to feel good, happy, relaxed, and physically active. This is why people without any psychotic condition abuse the drug.

When the reward system of the brain is stimulated, it causes a sort of craving and compulsive behavior around the drug, which oftentimes results in addiction, unless you stop before it gets to that point.

However, in schizophrenia patients, seroquel works by affecting the production of dopamine and serotonin, just as stated before.

Excess dopamine in the mesolimbic tract is believed to be responsible for the positive symptoms seen in schizophrenics, so the introduction of seroquel causes an antagonist reaction causing the suppression of dopamine levels, consequently eliminating the symptoms.


Common side effects of sequel may include:

i) Mood changes

ii) Constipation

iii) Stomach upset

iv) Nausea

v) Vomiting

vi) Dizziness

vii) Lightheadedness 

viii) Dry mouth

ix) Weight gain

x) Speech problems

Side effects may become severe

When you notice any of the following signs, be sure to report them to your doctor.

i)Increased anxiety

ii) Difficulty swallowing

iii) Seizure

iv) Consistent trembling

v) Yellowing of skin and eye


Seroquel is taken as an immediate-release tablet and is produced in various strengths; 25mg, 50mg, 100mg, 209mg, 300mg, 400mg, and so on. 

Depending on who the drug is prescribed to, there are different dosage forms, for instance:

1. IN ADULTS: the standard dosage for adults is between 150-800mg per day, that is, taken 2 or 3 times a day, depending on the condition being treated.

Also, depending on the condition the maximum dosage to be taken by adults is between 300-800 mg per day, more than this becomes an overdose.

2. IN CHILDREN: Children from 13 suffering schizophrenia and children from 10 who have mania episodes can be treated with seroquel as recommended by the Food and Drug Administration (FDA).

They recommend that the standard dosage for children ranges between 400-800 mg/day and the maximum dosage is 800mg/day, that is, taken 2-3 times a day.

This also depends on the condition being treated, for example, the maximum dose for children suffering schizophrenia is 600mg/day.

3. IN SCHIZOPHRENICS: for adults with schizophrenia (18 and above), the recommended dosage of sequel is 150-750mg/day, while for adolescents (13-17), 400-800mg of seroquel, taken 2-3 times a day is recommended.

4. IN BIPOLAR PATIENTS: Bipolar is a medical condition where a person switches between periods of depression and mania.

For the treatment of adults with mania episodes, 400-800mg/day of seroquel is to be divided into 2-3 times.

While for pediatric patients (10-17  years), 400-600mg divided into 2-3 doses per day is recommended. Adults treating depression are prescribed 300mg taken once a day at bedtime.


Seroquel has a half-life of 6-7 hours. 12 hours after seroquel has been administered, half of its dose will be removed almost instantly from the body. That is to say, if you took 10mg of seroquel at midnight, at 6 am 5mg of seroquel will be left in your body, and so on until there is no trace of the drug.

So, how long does seroquel stay in your system, seroquel can stay up to 12-24 hours for either half or all the drugs to completely leave your system.

When you stop taking seroquel, a drug test may give a negative result, but in truth, it can take a while for seroquel metabolites to be removed effectively from your system. However, certain factors may affect how long seroquel stays in your body. 


Factors such as : Age, weight, dosage, duration of administration and drug interaction

AGE: Older people have a lower rate of hepatic blood flow, so this alters the half-life of seroquel as there will be a reduced blood supply to the liver to carry out its function of metabolizing drugs.

WEIGHT: Yes, your weight can also affect how fast the drug is metabolized and removed from your system. It will take more time for seroquel to leave your body if you have a heavyweight. 

DOSAGE: The dosage you take also influences how long it will take for seroquel to leave your body. 25mg seroquel dose will leave the body faster than 200mg dose of seroquel.

DURATION OF ADMINISTRATION: This is a very essential factor. If you have been taking seroquel for a long time, then it will take even longer for it to leave your body.

DRUG INTERACTIONS: Certain drugs such as pimozide or thioridazine should not be taken along with seroquel, even though they are both antipsychotic medications, it may increase the risk and severity of the side effects of the condition suffered.

Always consult with your doctor before you begin medication and before you stop medication and be sure to take your medications just as prescribed by your doctor. Avoid overdosing or misuse of any drug.

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