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If you’re taking fluoxetine, it’s important to know more about it, including how long fluoxetine stays in your body. The following information from the FDA reflects fluoxetine’s half-life:

Slow elimination half-life: 1 to 3 days after acute administration; 4 to 6 days after chronic administration

Mean terminal half-life: 8.6 days after single dose; 9.3 days after multiple doses

  • “Steady-state levels” after prolonged administration: 4 to 5 weeks


What is the half-life of fluoxetine?

The average half-life of fluoxetine is about 2 to 4 days. It generally takes around 2 to 4 weeks for fluoxetine to have an antidepressant effect, according to a 2020 study.

How long does fluoxetine stay in your system?

It takes about 25 days for fluoxetine to get out of your body, according to Harvard Health.

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