escitalopram
Lexapro (escitalopram) is a selective serotonin reuptake inhibitor used for major depressive disorder and generalized anxiety disorder. It blocks the serotonin transporter, leaving more serotonin available in the synapse to help restore mood balance. It is one of the most selective SSRIs available.
This page is based on FDA prescribing information for escitalopram, cross-checked with DailyMed labeling, MedlinePlus, and the National Cancer Institute dictionary; the mechanism is explained in plain language, and analogies are used only where they stay accurate.
The label warns about this, in its own words: “In pooled analyses of placebo-controlled trials of antidepressant drugs (SSRIs and other antidepressant classes) that included approximately 77,000 adult patients and 4,500 pediatric patients, the incidence of suicidal thoughts and behaviors in the antidepressant-treated patients age 24 years and younger was greater than in placebo-treated patients.” It also says, in the same section: “Counsel family members or caregivers of patients to monitor for changes in behavior and to alert the healthcare provider.”
How it works
Explains what the medicine does in the body, not dosing, side effects, or safety.
An analogy
Think of serotonin as a message passed between brain cells. After the message is delivered, a recycling pump called SERT quickly pulls the serotonin back in, ending the signal. Escitalopram plugs that pump, so the message stays in the gap longer and keeps being heard — helping the brain's mood circuits work more steadily.
In simple terms
Escitalopram belongs to a family of antidepressants called selective serotonin reuptake inhibitors, or SSRIs. Brain cells communicate using a chemical called serotonin, which is released into the gap between cells and then quickly pulled back in by a recycling pump. Escitalopram blocks that pump, so serotonin stays in the gap longer and continues to stimulate the next cell. Over several weeks, this steady increase in serotonin signaling helps lift mood and reduce excessive worry. Escitalopram is the active mirror-image form of citalopram and is considered one of the most selective SSRIs, meaning it mainly affects serotonin with little effect on other brain chemicals.
In depth
Escitalopram is the S-enantiomer of citalopram and a potent, selective inhibitor of the serotonin transporter (SERT). It binds the primary orthosteric site on SERT and, uniquely among SSRIs, also occupies a secondary allosteric site that stabilizes drug–transporter binding and prolongs serotonin reuptake inhibition. The resulting increase in extracellular serotonin enhances signaling at 5-HT1A autoreceptors and post-synaptic 5-HT receptors, with downstream desensitization of autoreceptors and adaptive changes in gene expression thought to underlie the therapeutic lag of several weeks. Escitalopram has negligible affinity for muscarinic, histaminergic, or adrenergic receptors at therapeutic doses.
See it in motion
A schematic animation of the mechanism — simplified for clarity, not drawn to scale.
Brain cells communicate using a chemical called serotonin, which is released into the gap between cells and then quickly pulled back in by a recycling pump.
- Think of serotonin as a message passed between brain cells.
- After the message is delivered, a recycling pump called SERT quickly pulls the serotonin back in, ending the signal.
- Escitalopram blocks that pump, so serotonin stays in the gap longer and continues to stimulate the next cell.
- Over several weeks, this steady increase in serotonin signaling helps lift mood and reduce excessive worry.
Target: Serotonin transporter (SERT)
A membrane pump that recycles serotonin back into the presynaptic neuron; blocking it leaves more serotonin in the synapse to keep signaling.
Approved uses
Approved uses differ by country and change over time. Always follow your local prescribing information.
Approved uses in United States
FDA- Treatment of major depressive disorder in adults and pediatric patients 12 years of age and older
- Treatment of generalized anxiety disorder in adults
Approved uses in United States
DailyMed- Treatment of major depressive disorder in adults and pediatric patients 12 years of age and older
- Treatment of generalized anxiety disorder in adults
Approved uses in United States
MedlinePlus- Treatment of depression and generalized anxiety disorder
Approved uses in United States
NCI- Antidepressant and anxiolytic agent; selective serotonin reuptake inhibitor
Official sources
The statements on this page trace back to these records.
- U.S. Food and Drug Administration: escitalopram prescribing information
U.S. Food and Drug Administration
- DailyMed: escitalopram oxalate labeling
DailyMed, U.S. National Library of Medicine
- MedlinePlus: escitalopram
MedlinePlus, U.S. National Library of Medicine
- National Cancer Institute: escitalopram
National Cancer Institute
This page explains how the medicine works — it isn’t the patient leaflet. For anything that applies to you, read the leaflet that came with your medicine or ask your pharmacist.
MedUnfold provides educational content and is not medical advice. Always follow your local prescribing information and healthcare professional.