Since the start of the pandemic, women have reported noticing changes to their monthly cycles.

Last September (2021), an article in the British Medical Journal by Dr Viki Male reported that these changes are mostly temporary, and periods return to normal after a single cycle[1].

An article published at the beginning of January (2022) in the Obstetrics & Gynecology Journal has confirmed the COVID-19 vaccine can impact the length of monthly cycles, but not period length[2].

The article confirms on average people could experience a change in overall cycle duration by less than one day following their vaccination, but no change to their period length. Again these changes are identified as temporary and cycle length resolves quickly in following cycles.

However, we are to be cautious of the latest report; it only analyzed data of 4000 people in the USA, and its conclusion is based on average calculations which flatten the overall numbers. According to Refinery29, nearly 10% of people included in the research experienced a more significant change[3].

These initial reports are reassuring given the height of uncertainty of how women are being impacted by the pandemic, but more research is needed to understand the full impact.

Women need to know how they are being impacted by all aspects of the pandemic, including how the vaccine can impact their periods. Collecting data on the effects of medical interventions on women cannot be treated as an afterthought in future research.

Vaccine hesitancy among young women is largely driven by false claims that the COVID-19 vaccines could harm their chances of future pregnancy.

We support calls for further research to better understand how the pandemic is impacting our lives.


[1] Menstrual changes after COVID-19 vaccination, Dr V Male, BMJ 2021


[2] Association between menstrual cycle length and coronavirus disease 2019 vaccination, Obstetrics & Gynecology Journal 2022


[3] Finally we know how COVID vaccines impacted periods