Lexapro vs. Fluoxetine

See how Lexapro and Fluoxetine compare on approved uses, dosing, side effects, and cost.

Key Takeaways

  • Lexapro and fluoxetine are both SSRIs for depression, but fluoxetine has FDA approval for more conditions, including OCD, panic disorder, and bulimia nervosa.

  • Lexapro tends to cause less insomnia and fewer GI side effects than fluoxetine, which is linked to higher rates of insomnia, nausea, and headache.

  • Fluoxetine's generic price is far lower than Lexapro's, though Lexapro has a simpler once-daily schedule with only one dose increase.

Lexapro vs. Fluoxetine Drug Summary

Lexapro

Lexapro (escitalopram) is a selective serotonin reuptake inhibitor (SSRI) approved to treat major depressive disorder in adults and adolescents and generalized anxiety disorder in adults. It comes as a tablet or oral solution taken once daily, usually starting at 10 mg and increasing to 20 mg after two weeks if needed.

Fluoxetine

Fluoxetine is an SSRI approved for major depressive disorder, obsessive-compulsive disorder, panic disorder, and bulimia nervosa, and is also used with olanzapine for bipolar depression. It comes as a capsule, tablet, or liquid, usually taken once daily, with an optional once-weekly maintenance dose for some patients.

Lexapro vs. Fluoxetine Side Effects

Lexapro

Most common
Nausea (15%)
Insomnia (9%)
Somnolence (6%)
Ejaculation disorder (9%)

Fluoxetine

Most common
Nausea (up to 21%)
Insomnia (up to 33%)
Somnolence (up to 13%)
Headache (up to 21%)

Lexapro vs. Fluoxetine Dosage

Lexapro

Dosage
Dosage Table
STAGE DOSE WHEN
Starting dose 10 mg once daily Week 1
Maximum dose 20 mg once daily Week 2 onward
Dose changes 1 increase Every week

Fluoxetine

Dosage
Dosage Table
STAGE DOSE WHEN
Starting dose 10 mg once daily Week 1
Maximum dose 90 mg once weekly If needed
Dose changes 4 increases Every week

Lexapro vs. Fluoxetine Indications

Lexapro

Lexapro is FDA-approved for major depressive disorder in adults and adolescents ages 12 to 17, and for generalized anxiety disorder in adults. It is not approved for depression in children under 12 or for anxiety in children of any age.

  • Major depressive disorder in adults

  • Major depressive disorder in adolescents 12-17

  • Generalized anxiety disorder in adults

Fluoxetine

Fluoxetine is FDA-approved for major depressive disorder in adults and children 8 and older, plus OCD, panic disorder, and bulimia nervosa. It's also approved with olanzapine for bipolar depression, and is used off-label for premenstrual dysphoric disorder and binge eating disorder.

  • Major depressive disorder (adults and children 8+)

  • Obsessive-compulsive disorder (ages 7+)

  • Panic disorder and bulimia nervosa in adults

Lexapro vs. Fluoxetine Pros and Cons

Lexapro

Lexapro offers simple once-daily dosing with only one dose increase, and its side effect profile leans toward sexual dysfunction and sweating rather than significant insomnia or stomach upset. It has a shorter half-life than fluoxetine, which lowers interaction risk but means missed doses can cause withdrawal symptoms sooner.

Pros

  • Fewer drug interactions than fluoxetine

  • Simple once-daily dosing with only one increase

  • Lower rates of insomnia and GI side effects

  • Approved for both depression and anxiety

Cons

  • Costs more than fluoxetine, even generic ($440-603 vs $25-60/month)

  • Approved for fewer conditions than fluoxetine

  • Sexual side effects (ejaculation disorder) are common

  • Shorter half-life brings on withdrawal symptoms sooner

Fluoxetine

Fluoxetine covers the broadest range of approved uses among SSRIs and has decades of long-term safety data behind it. Its long-acting metabolite buffers missed doses but also raises the chance of drug interactions and means side effects can persist longer after stopping.

Pros

  • FDA-approved for OCD, panic disorder, and bulimia

  • Long half-life buffers the effect of missed doses

  • Extremely low generic cost ($25-60/month)

  • Optional once-weekly maintenance dosing

Cons

  • Higher rates of insomnia, nausea, and headache

  • More drug interactions from its long-acting metabolite

  • More complex dosing with several strength options

  • Not approved for generalized anxiety disorder

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