--- title: How quickly does fluoxetine start working for PMDD symptoms? | Niyora description: Very quickly. Fluoxetine improved irritability, sadness, anxiety, and mood swings within hours, with clear daily improvement by the second day. url: https://niyora.com/research/papers/rapid-response-to-fluoxetine-in-women-with-premenstrual-dysphoric-disorder-2012/ --- - [Niyora](https://niyora.com/) - [Research](https://niyora.com/research/) - [Library](https://niyora.com/research/library/) - How quickly does fluoxetine start working for PMDD symptoms? Cohort study, 2012 # How quickly does fluoxetine start working for PMDD symptoms? Very quickly. Fluoxetine improved irritability, sadness, anxiety, and mood swings within hours, with clear daily improvement by the second day. Moderate study design 12 women with PMDD receiving fluoxetine and 12 women with PMDD receiving no treatment ## What they did 12 women with PMDD took fluoxetine 20 mg daily during the luteal phase (the second half of the menstrual cycle). Another 12 women with PMDD received no treatment. Both groups rated their symptoms every hour before and after treatment, and also completed daily symptom questionnaires. ## What they found Hourly ratings showed significant improvement in irritability, sadness, anxiety, and mood swings after starting fluoxetine. Daily symptom scores improved significantly by the second day of taking the medication. The speed and pattern of improvement matched how symptoms naturally improve when menstruation starts. ## What it means for you Fluoxetine can work very fast for PMDD emotional symptoms, within days rather than weeks. This is much faster than how antidepressants usually work for depression. The study was small with only 12 women taking medication, so the results may not apply to everyone. 12 women receiving fluoxetine 20 mg daily dose second day when symptom improvement was clear ## About the study Original title Rapid response to fluoxetine in women with premenstrual dysphoric disorder Authors Steinberg EM, Cardoso GM, Martinez PE et al. Journal Depression and anxiety Year 2012 Study design Cohort study What was tested Fluoxetine 20 mg daily during the luteal phase Open access Yes Read the paper [doi.org/10.1002/da.21959](https://doi.org/10.1002/da.21959) ## Topics [Premenstrual syndrome (PMS)](https://niyora.com/research/topics/condition-pms/)[Premenstrual dysphoric disorder (PMDD)](https://niyora.com/research/topics/condition-pmdd/)[Menstrual cycle and mood](https://niyora.com/research/topics/condition-cycle-mood/)[Low mood and depression](https://niyora.com/research/topics/symptom-depression-mood/)[Anxiety and tension](https://niyora.com/research/topics/symptom-anxiety/)[Irritability and anger](https://niyora.com/research/topics/symptom-irritability-anger/)[SSRIs and antidepressants](https://niyora.com/research/topics/treatment-ssri/)[Major depressive disorder](https://niyora.com/research/topics/comorbidity-major-depression/)[Anxiety disorders and OCD](https://niyora.com/research/topics/comorbidity-anxiety-disorders/) Research tells you what helps on average. Niyora helps on the day it hits. Calm down, see it another way, and decide what to say, with a PMS and PMDD app built by a doctor. ## Related studies Review, 1999 Is premenstrual dysphoric disorder a distinct clinical disorder? Survey study, 2001 How common is premenstrual dysphoric disorder and how is it related to other psychiatric conditions? Study, 2026 Do anxiety and depression get worse before your period if you already have a mental health condition? Study, 2026 What are premenstrual syndrome and premenstrual dysphoric disorder? Randomised trial, 1999 Do SSRIs reduce premenstrual dysphoria symptoms? Randomised trial, 1995 Does fluoxetine help premenstrual dysphoria? Ask AI about this page Copy prompt ChatGPT ↗ Claude ↗ Perplexity ↗ Google AI Mode ↗ Grok ↗