TaperCommunityfluoxetine
Boxed Warning
Suicidality risk in children, adolescents, and young adults under 25 during initial treatment.
Fluoxetine was the first SSRI approved in the US and remains one of the most widely prescribed antidepressants. It is approved for major depressive disorder, OCD, panic disorder, bulimia nervosa, and bipolar depression (in combination with olanzapine).
10mg, 20mg, 40mg, 60mg
Capsules: 10mg, 20mg, 40mg; Tablets: 10mg, 20mg, 60mg; Oral solution: 20mg/5mL; Delayed-release capsules (weekly): 90mg
Category C (risk cannot be ruled out)
Selective serotonin reuptake inhibitor (SSRI) that blocks the serotonin transporter (SERT). Its active metabolite norfluoxetine is also a potent SSRI, contributing to an extremely long effective half-life.
Very long half-life makes it one of the more forgiving SSRIs to taper. A gradual reduction is still recommended.
Long half-life provides built-in buffering. Still recommended to taper gradually rather than abrupt stop.
Evidence-based phased reduction schedule. Always taper under medical supervision.
| Phase | Duration | Notes |
|---|---|---|
| Initial reductions | 4-6 weeks | Available capsule strengths allow straightforward reductions. The long half-life buffers each step. |
| Middle reductions | 4-6 weeks | Smaller capsule strengths or oral solution may be used. Most tolerate this phase well. |
| Final reductions | 4-8 weeks | The long half-life makes Prozac one of the more forgiving SSRIs to taper. Work with your prescriber on the final steps. |
3-7 days after dose reduction (delayed by long half-life)
1-2 weeks
2-4 weeks
Uncommon due to long half-life. Some report emotional flatness for 4-6 weeks. Fluoxetine has the mildest withdrawal profile of all SSRIs.
Practical insights shared by members tapering Prozac. Not medical advice — always consult your prescriber.
Toxicity
Serotonin syndrome at supratherapeutic doses. QT prolongation rarely reported. Lower toxicity in overdose compared to TCAs.
Pharmacokinetics
Well absorbed after oral administration. Bioavailability ~72%. Tmax 6–8 hours. Food slightly delays absorption but does not affect overall extent.
~20–45 L/kg
Hepatic via CYP2D6 (primary) and CYP2C9 to the active metabolite norfluoxetine. Fluoxetine is a potent CYP2D6 inhibitor.
Renal (~80%, with ~2.5% as unchanged fluoxetine and ~10% as norfluoxetine). Fecal (~15%).
~94.5%
Apparent oral clearance ~600 mL/min; decreases with chronic dosing due to CYP2D6 inhibition.
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