---
title: Does taking fluoxetine only during the premenstrual period work as well as taking it every day?
description: Both daily and premenstrual-only fluoxetine were effective for PMDD. Intermittent dosing appears to work nearly as well as daily dosing while causing fewer si
url: https://niyora.com/research/papers/intermittent-fluoxetine-dosing-in-the-treatment-of-women-with-premenstrual-1997/
---

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- Does taking fluoxetine only during the premenstrual period work as well as taking it every day?

Randomised trial, 1997

# Does taking fluoxetine only during the premenstrual period work as well as taking it every day?

Both daily and premenstrual-only fluoxetine were effective for PMDD. Intermittent dosing appears to work nearly as well as daily dosing while causing fewer side effects.

 Moderate study design

48 women with confirmed PMDD: 24 with a history of mood disorders or alcoholism, and 24 with no psychiatric history

## What they did

Researchers compared two ways of taking fluoxetine in 48 women with PMDD. One group of 24 took it every day at 20 mg, and another group of 24 took 20 mg for 14 days before their period each month. Both groups took medication for 3 menstrual cycles.

## What they found

In the daily group, 16 of 24 women (66.7%) responded well to treatment. In the premenstrual-only group, 18 of 24 women (75.0%) responded well. The intermittent group had mostly no side effects.

## What it means for you

Taking fluoxetine only during the premenstrual phase may be just as effective as daily dosing and causes fewer unwanted effects, which could appeal to women who prefer shorter-term treatment. The study only looked at 3 menstrual cycles and one dose of fluoxetine.

24

women per treatment group

75.0%

response rate with intermittent dosing

66.7%

response rate with daily dosing

## About the study

Original title Intermittent fluoxetine dosing in the treatment of women with premenstrual dysphoria Authors Steiner M, Korzekwa M, Lamont J et al. Journal Psychopharmacology bulletin Year 1997 Study design Randomised trial Participants 24 What was tested Fluoxetine 20 mg daily (24 women) versus fluoxetine 20 mg for 14 days before the period (24 women) Read the paper [https://pubmed.ncbi.nlm.nih.gov/9493491/](https://pubmed.ncbi.nlm.nih.gov/9493491/)

## Topics

[Premenstrual syndrome (PMS)](https://niyora.com/research/topics/condition-pms/)[Premenstrual dysphoric disorder (PMDD)](https://niyora.com/research/topics/condition-pmdd/)[Low mood and depression](https://niyora.com/research/topics/symptom-depression-mood/)[SSRIs and antidepressants](https://niyora.com/research/topics/treatment-ssri/)

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Calm down, see it another way, and decide what to say, with a PMS and PMDD app built by a doctor.

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