Lexapro (escitalopram) takes roughly 6 to 7 days to fully clear your system after your last dose. The drug has a half-life of 27 to 32 hours, meaning your body eliminates about half of it every day and a half. After five to six half-lives, the amount remaining is negligible, putting total clearance in the range of six to eight days for most people.
How the Half-Life Works
Every 27 to 32 hours, your liver breaks down about half of the escitalopram circulating in your blood. If you took your last 10 mg dose, roughly 5 mg worth of active drug remains after about 30 hours. Another 30 hours later, about 2.5 mg remains. This halving continues until the amount is too small to have any meaningful effect.
Pharmacologists generally consider a drug “out of your system” after five half-lives, when over 96% has been eliminated. For Lexapro, five half-lives equals about 5.6 to 6.7 days. Waiting a full six half-lives gets you above 98% clearance, or roughly 7 to 8 days.
Your Body’s Metabolite Hangs Around Longer
When your liver processes escitalopram, it produces a byproduct called desmethylcitalopram. This metabolite has a much longer half-life of about 77 to 79 hours, meaning it lingers in your blood for up to two weeks or more after your final dose. The good news: this metabolite is pharmacologically inactive, so it isn’t contributing to the drug’s antidepressant effects or side effects while it clears out. It’s essentially a leftover your body is still flushing.
Factors That Slow Clearance
Not everyone clears Lexapro at the same speed. Several factors can push that 6-to-8-day window significantly longer.
Age: Adults 65 and older eliminate escitalopram about 50% more slowly than younger adults. The half-life in older people can stretch to 40 hours or beyond, which means full clearance could take 9 to 10 days.
Liver function: Your liver does the heavy lifting when it comes to breaking down escitalopram. In people with reduced liver function, clearance drops by about 37% and the half-life roughly doubles. That could extend total elimination to nearly two weeks.
Genetics: A liver enzyme called CYP2C19 is the main tool your body uses to metabolize Lexapro. People carry different genetic variants of this enzyme. Slow metabolizers end up with higher drug concentrations in their blood at the same dose, meaning clearance takes longer. Fast metabolizers process the drug more quickly and may clear it in fewer days. Genetic testing can identify your metabolizer status, and clinical guidelines already recommend considering it when prescribing this class of medication.
Dose and duration: Higher doses leave more drug to eliminate, and long-term use means the drug has reached a steady concentration throughout your tissues. Both can add a day or two to your clearance timeline compared to someone who took a low dose for a short period.
Withdrawal Can Start Before It Fully Clears
You don’t need to wait for Lexapro to leave your system entirely before feeling the effects of stopping it. Withdrawal symptoms typically begin one to three days after your last dose, right as blood levels start dropping meaningfully. Common symptoms include dizziness, irritability, nausea, headache, and a sensation sometimes described as “brain zaps.”
For most people, these symptoms resolve within one to two weeks. In some cases, particularly after long-term use or abrupt discontinuation, they can persist longer. This is why doctors typically recommend tapering the dose gradually rather than stopping all at once. Tapering lets your brain adjust to falling serotonin levels incrementally instead of all at once.
Lexapro and Drug Testing
If you’re wondering whether Lexapro will show up on a drug test, it won’t. Standard drug screens test for substances of abuse like opioids, amphetamines, benzodiazepines, and cannabis. Antidepressants are not included in these panels. Some SSRIs in the same class can trigger false positives for other substances, but Lexapro specifically does not produce false-positive results for any drug category. You don’t need to worry about it affecting employment or legal screenings.
Timeline at a Glance
- 1 to 3 days: Blood levels drop noticeably; withdrawal symptoms may begin
- 6 to 8 days: Over 96% of escitalopram eliminated in healthy adults
- 9 to 10 days: Typical clearance window for adults over 65
- Up to 2 weeks: Clearance in people with liver impairment; inactive metabolite may still be detectable
For the average healthy adult, a week is a reasonable estimate for when Lexapro is effectively gone. If you’re older, have liver concerns, or have been told you’re a slow metabolizer, allow closer to two weeks.