Lexapro (escitalopram oxalate) is the 20th most commonly prescribed drug in the United States. In 2017 alone, there were over 25,960,468 prescriptions. Considering how popular this drug is right now, it pays to know a little bit more about this medication, including how long Lexapro stays in your system.
How long does Lexapro stay in your system?
It takes about 27 to 32 hours (the mean effective half-life of escitalopram) for the body to eliminate half of this drug. That means it could take about 6.1 days to 7.3 days for the body to clear most, if not all, of this antidepressant.
Lexapro is likely detectable in your system for the following time frames:
Urine: After an oral dose, about 8% of the dose exits the body in urine as escitalopram and 10% of the dose as S-desmethylcitalopram, one of Lexapro’s major metabolites; clearance following an oral dose is 600 mL/min, with 7% of that occurring through the renal system. Note that it is not common to screen for Lexapro with urine tests.
Plasma/Blood: Peak blood concentration occurs after 5 hours following a single 20 mg oral dose.
Hair: Potentially up to 90 days (3 months) after last use, although accuracy may be low with hair tests.
(Numbers above are merely estimates, and may vary based on several factors, such as age and other medical conditions.)
The FDA states the following information regarding Lexapro half-life:
Time to steady-state: about 1 week (1/day dosage)
Mean terminal half-life: 27-32 hours
This medication has an absolute bioavailability of about 80% (estimates based on IV citalopram). The body primarily metabolizes it through the liver via the enzymes (specialized proteins) CYP3A4 and CYP2C19.
How long does it take for Lexapro to get in your system?
In medicine, steady-state refers to when the body’s concentration of a certain medication is stable. It can take approximately 7 to 10 days for Lexapro to reach steady-state, and up to 6 weeks for someone to feel its full effects.
Does Lexapro wear off?
Yes, Lexapro eventually wears off. However, abruptly stopping this medication can lead to negative withdrawal side effects. As a result, most doctors instruct their patients to taper off this drug, which could take a few weeks.
How long do side effects of Lexapro last?
It usually takes 4 to 6 weeks for Lexapro to start working; many side effects fade after this period. People who continue to experience unpleasant side effects should talk to their doctors.