--- title: Does COVID-19 vaccination change the menstrual cycle? | Niyora description: About 25% of vaccinated people reported temporary menstrual changes, most after the second dose. The vaccines are safe and effective, but the study could not url: https://niyora.com/research/papers/covid-19-vaccination-and-changes-in-the-menstrual-cycle-among-vaccinated-persons-2023/ --- - [Niyora](https://niyora.com/) - [Research](https://niyora.com/research/) - [Library](https://niyora.com/research/library/) - Does COVID-19 vaccination change the menstrual cycle? Cohort study, 2023 # Does COVID-19 vaccination change the menstrual cycle? About 25% of vaccinated people reported temporary menstrual changes, most after the second dose. The vaccines are safe and effective, but the study could not determine whether changes were caused by the vaccine or are normal cycle variation. Moderate study design 545 vaccinated people, mostly aged 26-35 years, mostly White and non-Hispanic ## What they did Followed 545 vaccinated people who were unpregnant and pre-menopausal. Collected self-reported data on menstrual changes from May to December 2021. ## What they found 25% reported menstrual changes. Most changes occurred after the second dose (56%). Common changes were irregular periods (43%), increased premenstrual symptoms (34%), increased menstrual pain (30%), and heavy or prolonged bleeding (31%). High stress and higher BMI were linked to greater odds of changes. Prior COVID-19 infection was linked to lower odds. ## What it means for you If you get a COVID-19 vaccine, there is about a 1 in 4 chance of temporary menstrual changes, especially after the second dose. The main limitation is that people reported changes themselves rather than being medically measured, and the study cannot determine whether the vaccine caused the changes or they are normal cycle variation. 25% reported menstrual changes after vaccination 56% reported changes after second dose 43% reported irregular menstruation ## About the study Original title COVID-19 vaccination and changes in the menstrual cycle among vaccinated persons Authors Farland LV, Khan SM, Shilen A et al. Journal Fertility and sterility Year 2023 Study design Cohort study Participants 545 What was tested COVID-19 vaccination (Pfizer-BioNTech, Moderna, or Johnson & Johnson) Open access Yes Read the paper [doi.org/10.1016/j.fertnstert.2022.12.023](https://doi.org/10.1016/j.fertnstert.2022.12.023) ## Topics [Premenstrual syndrome (PMS)](https://niyora.com/research/topics/condition-pms/)[Dysmenorrhea and period pain](https://niyora.com/research/topics/condition-dysmenorrhea/)[Pain and headache](https://niyora.com/research/topics/symptom-pain/)[Stress](https://niyora.com/research/topics/symptom-stress/)[Pregnancy and postpartum](https://niyora.com/research/topics/comorbidity-postpartum/)[Work and productivity](https://niyora.com/research/topics/life-area-work/) 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 Case-control study, 2014 How common is severe period pain and what causes it? Survey study, 2015 How common is physical stress and pain during the menstrual cycle? Systematic review, 2025 Does digital healthcare help manage period pain and PMS? Cohort study, 2025 How common is PMS in Chinese teenage girls, and what factors are linked to it? Systematic review, 2024 Does yoga help reduce PMS symptoms? Review, 2023 What treatments help mental and physical health problems linked to the menstrual cycle? Ask AI about this page Copy prompt ChatGPT ↗ Claude ↗ Perplexity ↗ Google AI Mode ↗ Grok ↗