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How COVID-19 Affects Menstrual Cycles and What to Track

COVID-19 infection and vaccination are associated with temporary menstrual changes. Learn what studies documented, why changes happen, and when to seek

When reports of post COVID menstrual changes began circulating in 2020 and 2021, the initial response from many clinical institutions was skepticism. Within two years, multiple large scale studies using tracked menstrual data had documented that the changes were real, statistically significant, and mechanistically plausible. This is a situation where patient reported experiences and tracking data drove scientific inquiry — and the data confirmed what people were describing. This guide covers what the research actually found, why COVID affects cycles, what changes are typical and temporary, and what should prompt a clinical conversation. What the Research Found Several independent research groups have now published findings on COVID 19 and menstrual changes, using different datasets and methodologies. Their results are broadly consistent. The Apple Women's Health Study , conducted in partnership with Harvard T.H. Chan School of Public Health and the NIH, analyzed menstrual tracking data from thousands of participants who reported COVID 19 infection. The study found that COVID 19 infection was associated with delayed menstruation in the cycle following infection, and that the effect