Lexapro is the brand name for escitalopram. It's one of the most widely prescribed SSRIs in the world, used as a first-line treatment for depression and generalised anxiety disorder. It's also commonly used for panic disorder, social anxiety, OCD, and PMDD. If a GP is going to put someone on an antidepressant for the first time, this is usually the one, because it tends to be the best-tolerated SSRI with the cleanest drug interaction profile.
It works by raising serotonin levels in the brain, which over weeks lifts mood, dampens anxiety, and quiets the loops of rumination, worry, and panic that drive these conditions. Most people on it describe the effect as turning the volume down on the bad stuff, life still happens but it stops hitting as hard.
It's a prescription drug, takes 4-6 weeks to reach full effect, and stopping abruptly causes a real withdrawal syndrome. This is not a compound to start or stop on a whim.
Deep-dive
Escitalopram works almost entirely through one mechanism, which is part of why it's so clean compared to other antidepressants.
A quick note on the name. Escitalopram is the purified S-isomer of citalopram (sold as Celexa). Citalopram is a 50/50 mix of two mirror-image molecules, only one of which actually does anything useful on serotonin. Lexapro is just that active half on its own, which is why it works at roughly half the dose, has fewer cardiac concerns, and tends to have slightly better efficacy and faster onset.
Serotonin reuptake inhibition. Escitalopram is the most selective SSRI on the market, meaning it binds the serotonin transporter (SERT) with very high affinity and barely touches any other receptor. It also has an allosteric binding site on SERT in addition to the primary site, which is unique to escitalopram and is part of why it edges out citalopram and other SSRIs. By blocking SERT, escitalopram raises synaptic serotonin, and over weeks this drives the downstream changes (BDNF upregulation, receptor adaptation, neurogenesis in the hippocampus) that probably underlie the actual antidepressant and anti-anxiety effect. The acute serotonin bump is not the therapeutic effect, the slow adaptation to it is.
Depression. This is the indication with the strongest evidence. The 2018 Cipriani network meta-analysis of 522 trials and over 116,000 patients ranked escitalopram among the most effective and best-tolerated antidepressants, alongside agomelatine, mirtazapine, paroxetine, and vortioxetine. Head-to-head with citalopram, escitalopram showed greater response and remission rates at 8 weeks. In real-world practice the effect size for any given person is modest, number needed to treat is around 7-9 for response, which means most people improve but a meaningful minority don't.
Generalised anxiety disorder. Multiple placebo-controlled trials have established escitalopram as effective for GAD, with response usually emerging by week 4 and continuing to improve out to 6 months. It's a first-line choice for GAD alongside duloxetine, sertraline, and venlafaxine. The anxiety symptoms often improve before the mood symptoms do, which is one reason people stay on it even when the depressive component was the original target.
Panic disorder. A 10-week placebo-controlled trial at 5-20 mg/day showed significant reductions in panic attack frequency. The standard approach is to start lower than you would for depression (5 mg) because SSRIs can transiently worsen anxiety and trigger panic in the first 1-2 weeks. Titrate slowly, expect a rough start, and pair with short-term coverage if needed.
OCD. Trials support escitalopram for OCD at higher doses (20 mg/day, sometimes 30-40 mg off-label), with effects emerging slower than for depression. Fluvoxamine and sertraline are usually preferred for OCD as first-line, but escitalopram is a reasonable alternative if those aren't tolerated.
PMDD. Continuous and luteal-phase-only dosing both work. Luteal-phase dosing (taking it only from ovulation to menses) is uniquely effective with SSRIs in PMDD compared to other antidepressant indications. The effect is fast (often within 1-2 cycles) which suggests a different mechanism than the slow BDNF-mediated effect in depression, probably direct modulation of allopregnanolone-sensitive GABA signalling.
Social anxiety. Effective in placebo-controlled trials and a reasonable first-line choice alongside sertraline and paroxetine.
Sexual side effects. Probably the most discussed downside. Across SSRIs, rates of sexual dysfunction are substantially higher than placebo, and escitalopram sits roughly in the middle of the class, around 30-40% of patients in honest reporting versus the low single digits reported on standard adverse event forms. The discrepancy is because people don't volunteer this stuff unless asked directly. Effects include decreased libido, delayed orgasm, anorgasmia, and erectile difficulty. There's also a small but real population reporting post-SSRI sexual dysfunction (PSSD), where sexual side effects persist after discontinuation. The mechanism isn't fully understood, prevalence is unclear, and it's not predictable. It's worth knowing about before starting.
Emotional blunting. A reduction in emotional reactivity in both directions, positive and negative. For someone with severe anxiety or depression this is often welcome at first, the volume on everything is lower. Long-term, it's the most common reason people choose to come off. Not feeling sad is one thing. Not feeling joy or connection or motivation is another. Around 40-60% of long-term SSRI users report some degree of emotional blunting. Whether this is the drug or the residual depression is genuinely debated.
Women. Escitalopram is one of the better-studied SSRIs in women. Pharmacokinetic differences between sexes are small, and dosing is typically the same. Where things differ is around the menstrual cycle, hormonal contraception, pregnancy, and perimenopause. In PMDD specifically, luteal-phase dosing works, which is a uniquely female protocol. Hormonal contraception doesn't significantly alter escitalopram levels. Perimenopausal women with new or worsening anxiety and depression often respond well to escitalopram, and there's good evidence it helps with vasomotor symptoms (hot flushes) at 10-20 mg/day, sometimes used off-label for that purpose alone. Sexual side effects in women are underreported but real, decreased libido and anorgasmia are common. The narrative that women don't experience SSRI sexual side effects is mostly an artefact of who got asked in early trials.
Pregnancy and breastfeeding. Observational data doesn't show a clear increase in major congenital malformations, but third-trimester SSRI exposure carries a small increased risk of neonatal pulmonary hypertension (absolute risk roughly 3 per 1,000 vs 1 per 1,000 baseline) and a transient post-natal adaptation syndrome (jitteriness, feeding difficulty, brief respiratory issues) in around 30% of exposed neonates. Most cases resolve within days. For breastfeeding, transfer into milk is low, with relative infant doses around 5%, and most infants have undetectable serum levels. The decision is individualised. Stopping in pregnancy carries its own relapse risk, especially in someone with a history of severe depression.
Older adults. Pharmacokinetics shift with age, clearance drops by around 25-50%, and the FDA recommends a maximum of 10 mg/day in adults over 65. Hyponatraemia risk is also higher in this group. Start at 5 mg, go slowly, watch sodium.
Cardiac. Escitalopram has a small dose-dependent effect on the QT interval, enough that the FDA capped citalopram at 40 mg in adults and 20 mg in older adults. Escitalopram is cleaner here than citalopram but still worth knowing about if you have cardiac history or are on other QT-prolonging drugs.
Comparison to other SSRIs. This is the most-prescribed SSRI for a reason. Compared to sertraline, escitalopram tends to be slightly more sedating and has slightly fewer GI side effects, but sertraline often has less sexual dysfunction. Compared to paroxetine, escitalopram has a much milder discontinuation syndrome and fewer anticholinergic effects. Compared to fluoxetine, escitalopram works faster and doesn't have the long half-life that complicates switching drugs. Compared to fluvoxamine, escitalopram has a vastly cleaner interaction profile (fluvoxamine inhibits CYP1A2 strongly, escitalopram barely touches CYP enzymes). The trade-off is that escitalopram is just an SSRI, it doesn't have the sigma-1 angle that gives fluvoxamine its neuroprotective and anti-inflammatory reputation. If you want maximum cleanliness and predictability, escitalopram. If you want OCD specifically or the sigma-1 mechanism, fluvoxamine.
Combinations and stacks. Bupropion is commonly added to escitalopram to counter sexual side effects, emotional blunting, and low motivation. The combination is well-tolerated and one of the most-prescribed augmentation strategies in psychiatry. Mirtazapine is another common add-on, particularly when sleep and appetite are problems. Lithium and atypical antipsychotics are used for treatment-resistant cases but are specialist territory.
Dosage:
- Standard adult dose: 10-20 mg/day, usually taken once daily in the morning or evening. Start at 10 mg for depression and GAD, 5 mg for panic disorder or anxiety-dominant presentations to avoid early activation. Titrate after 1-2 weeks if needed. Maximum is 20 mg/day for most indications, occasionally 30 mg off-label for OCD
- Older adults: Maximum 10 mg/day, start at 5 mg. Clearance is lower and hyponatraemia risk is higher
- PMDD: Either continuous 10-20 mg/day or luteal-phase dosing starting 14 days before expected menses and stopping with bleed onset. Luteal-phase dosing has comparable efficacy with less total drug exposure
- Time to effect: Anxiety and physical symptoms (sleep, appetite) often improve in 1-2 weeks. Mood and cognitive symptoms take 4-6 weeks. Don't judge full response before week 6. If there's no movement by week 8 at adequate dose, it's reasonable to consider switching or augmenting
- Timing: Morning vs evening depends on whether it makes you sleepy or activated. Both are common. Try one for a week, if sleep is disrupted, switch
- Discontinuation: Never stop abruptly. Escitalopram has a 27-30 hour half-life which puts it in the moderate-risk category for discontinuation syndrome, better than paroxetine and venlafaxine but worse than fluoxetine. Standard guidance is to taper by 5 mg every 2-4 weeks. Hyperbolic tapering (smaller proportional reductions as you get lower) is increasingly recommended, especially after long-term use. The last 2-3 mg often cause the most withdrawal symptoms, which is why liquid escitalopram or compounded smaller doses are sometimes needed for the final taper
- Missing a dose: One missed dose isn't a big deal. Two or three in a row can trigger discontinuation symptoms. If you regularly forget, set a phone alarm
- Alcohol: Not a hard contraindication but the combination tends to amplify sedation, blunt the antidepressant effect, and worsen sleep architecture. Moderate use is generally tolerated
- Hard contraindications: MAOIs (need 14-day washout in either direction), pimozide, linezolid, methylene blue. Combining with serotonergic drugs (other SSRIs/SNRIs, MDMA, tramadol, triptans, dextromethorphan, St John's wort, 5-HTP) raises serotonin syndrome risk
- Lab interactions to know: Tramadol (raises serotonin syndrome risk and lowers seizure threshold), NSAIDs and aspirin (increased bleeding risk), warfarin (variable INR effects), QT-prolonging drugs (additive QT effect)
Here's what you can expect:
The first 1-2 weeks are often the worst. Nausea, headache, jitteriness, vivid dreams, sleep disruption, transiently increased anxiety or panic, mild GI symptoms. Most of this fades by week 3-4. This is the most common period for people to quit before the drug has had a chance to work, so it helps to know it's coming. Starting at 5 mg for the first week, even when the target is 10, makes a meaningful difference for sensitive people.
Real therapeutic benefit comes in stages. Physical symptoms (sleep, appetite, somatic anxiety) often shift first, by week 2-3. Mood, energy, and cognitive symptoms (rumination, hopelessness, difficulty concentrating) shift slower, often by week 4-6. The classic pattern with depression is that people feel more capable of action before they feel happier, which is one reason the early weeks have a slight increased risk of self-harm in vulnerable people, the depression hasn't lifted but the inertia has.
By month 2-3 most people have reached a stable state where the underlying symptom load is meaningfully lower and the side effects have settled into whatever the long-term baseline is going to be. Sexual side effects and emotional blunting usually persist as long as you're on the drug. GI symptoms, headaches, and sleep changes usually don't.
Most people stay on escitalopram for somewhere between 6 months and several years. The official recommendation for a first depressive episode is at least 6-9 months after full remission. For recurrent depression or anxiety, longer-term treatment is the norm. The decision of when to come off is genuinely hard and worth having with a prescriber rather than figuring out solo.
Side effects & risks:
- Nausea and GI symptoms are the most common early side effects, especially in the first 1-2 weeks. Taking with food helps. Usually settles by week 3-4
- Sleep disruption. Insomnia or vivid dreams in some, sedation in others. Bedtime dosing usually helps if it's sedating, morning dosing if it's activating
- Sexual dysfunction. Decreased libido, delayed orgasm, anorgasmia, erectile difficulty. Real-world rates are around 30-40% when patients are asked directly. Often persists for the duration of treatment. Bupropion augmentation, dose reduction, and drug holidays are sometimes used to manage it, all with mixed results
- Post-SSRI sexual dysfunction (PSSD). A small population reports sexual side effects persisting months or years after stopping. The mechanism isn't understood, prevalence isn't well established, and there's no proven treatment. Worth knowing exists, not worth panicking about
- Emotional blunting. Reduced reactivity in both directions. Hard to capture in trials but common in real-world reports. The most cited reason people choose to come off
- Weight gain. Modest, around 1-3 kg over 6-12 months in average studies, sometimes more. Less than mirtazapine or paroxetine, similar to sertraline and citalopram
- Sweating (antidepressant-induced excessive sweating). Dose-related, usually mild
- Yawning. A weird but well-documented side effect, harmless but sometimes noticeable
- Increased bleeding risk. SSRIs reduce platelet serotonin uptake, mildly impairing platelet function. Clinically relevant with NSAIDs, aspirin, anticoagulants, or in the perioperative period. Tell your surgeon before any procedure
- Hyponatraemia (low sodium). Uncommon but can be serious, more frequent in older adults, women, low body weight, and those on diuretics. Usually appears in the first month
- QT prolongation. Small and dose-dependent. Worth knowing if you have cardiac risk or are on other QT-prolonging drugs
- Bruxism (teeth grinding). Common and underdiscussed, can damage teeth over time. Often manageable with a night guard, dose reduction, or low-dose buspirone
- Activation and increased anxiety in the first 2 weeks. Counterintuitive but common, especially in panic-prone people. Usually transient. Starting at 5 mg mitigates this
- Suicidal ideation in young people. SSRIs carry a black-box warning for increased suicidal thoughts in patients under 25 during the first weeks. Risk is highest at initiation and dose changes, and is partly counterbalanced by the protective effect of treating the underlying disorder. Worth honest conversation if relevant
- Discontinuation syndrome. Common with abrupt cessation. Symptoms include dizziness, electric-shock sensations ("brain zaps"), nausea, irritability, vivid dreams, flu-like feelings. Usually peaks 2-5 days after stopping and resolves over 1-3 weeks, though a minority experience symptoms for much longer. Always taper, and slowly
- Serotonin syndrome. Potentially life-threatening reaction from excessive serotonergic activity. Risk rises with combinations (MAOIs, other SSRIs/SNRIs, tramadol, triptans, MDMA, dextromethorphan, linezolid, St John's wort). Symptoms include agitation, tremor, hyperthermia, autonomic instability, clonus
- Mania switch. In people with undiagnosed bipolar disorder, SSRIs can trigger manic or hypomanic episodes. Worth screening for bipolar history before starting
Blood markers
Sodium, baseline before starting and at 2-4 weeks if you're over 65, female, low body weight, or on a diuretic. SSRI-induced hyponatraemia usually appears in the first month and can be serious if missed.
Liver enzymes (ALT, AST), baseline. Escitalopram is hepatically metabolised, mostly via CYP2C19, and clearance drops with liver dysfunction. Recheck if symptoms suggest hepatic strain.
ECG, baseline if you have cardiac history, are over 65, or are on other QT-prolonging medications. Escitalopram is reasonably safe cardiac-wise but worth a baseline reference.
TSH and free T4, baseline. Hypothyroidism can present as treatment-resistant depression, so you want to rule it out before committing to long-term SSRI treatment.
CYP2C19 genotype is occasionally useful. Around 2-5% of people of European descent and up to 15-20% of East Asian descent are CYP2C19 poor metabolisers, which means escitalopram clears more slowly and standard doses produce higher exposure. If you're getting unusually strong side effects at 10 mg, this can explain it. Not a routine test but worth knowing exists.
Pregnancy test, before starting in women of reproductive age. Decisions about SSRI use in pregnancy are individualised and depend on knowing the situation.
For most healthy adults starting escitalopram, baseline sodium, liver enzymes, and TSH cover the meaningful ground. The bloodwork that actually matters most isn't standard chemistry, it's tracking response and side effects week to week with your prescriber and being honest about what's happening, including the awkward stuff.
Escitalopram is a prescription drug in essentially all jurisdictions.
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