Major Study Confirms COVID Vaccines Alter Women’s Periods

Submitted by Harold Saive

Major Study Confirms COVID Vaccines Alter Women’s Periods

Since Covid vaccines first became available more than a year and a half ago, women have been sounding alarms about the shots’ adverse effect on their menstruation.


Investigating trends in those who experience menstrual bleeding changes after SARS-CoV-2 vaccination

KATHARINE M. N. LEE HTTPS://ORCID.ORG/0000-0001-8894-9816ELEANOR J. JUNKINS HTTPS://ORCID.ORG/0000-0002-2878-6290CHONGLIANG LUOUROOBA A. FATIMAMARIA L. COX HTTPS://ORCID.ORG/0000-0001-9254-6577AND KATHRYN B. H. CLANCY HTTPS://ORCID.ORG/0000-0002-6901-254X Authors Info & Affiliations

15 Jul 2022 – Vol 8, Issue 28 — DOI: 10.1126/sciadv.abm7201


Early in 2021, many people began sharing that they experienced unexpected menstrual bleeding after SARS-CoV-2 inoculation. We investigated this emerging phenomenon of changed menstrual bleeding patterns among a convenience sample of currently and formerly menstruating people using a web-based survey. In this sample, 42% of people with regular menstrual cycles bled more heavily than usual, while 44% reported no change after being vaccinated. Among respondents who typically do not menstruate, 71% of people on long-acting reversible contraceptives, 39% of people on gender-affirming hormones, and 66% of postmenopausal people reported breakthrough bleeding. We found that increased/breakthrough bleeding was significantly associated with age, systemic vaccine side effects (fever and/or fatigue), history of pregnancy or birth, and ethnicity. Generally, changes to menstrual bleeding are not uncommon or dangerous, yet attention to these experiences is necessary to build trust in medicine.

This entry was posted in Uncategorized. Bookmark the permalink.