A new study published in the journal Science Advances offers one of the most comprehensive looks at menstrual changes post COVID-19 vaccine.
Two researchers, Kathryn Clancy and Katharine Lee, led the effort to study reported changes in menstrual bleeding in people who have been vaccinated against the virus.
Over 40 percent of survey respondents used for the study reported heavier bleeding within two weeks of getting the jab.
The COVID-19 vaccine temporarily impacted women and menstruating people’s periods, a new study suggests.
Reports of people experiencing changes to their menstrual cycles after receiving a COVID-19 vaccine started popping up in 2021. But little research had been done to assess the connection and all three COVID-19 vaccine manufactures denied any link between the inoculation and changes in menstrual bleeding or fertility.
Two researchers, Kathryn Clancy who is an associate professor of anthropology at the University of Illinois Urbana-Champaign and Katharine Lee, an anthropology professor at Tulane University, wanted to fill that gap in knowledge.
Among survey respondents, 71 percent of people on long-acting reversable birth control, 39 percent of people on gender-affirming hormones and 66 percent of post menopausal people reported breakthrough bleeding within two weeks of getting vaccinated.
“This might support the idea that spotting with the vaccine is not associated with fertility and the spotting is just a result of a new ‘stress’ on the reproductive system,” Shirazian told Changing America.
Both Lee and Clancy agree that vaccine-related changes to menstrual cycles are likely associated with “immune-related inflammatory pathways” and not hormonal changes.
Since the survey relied on self-reported responses to the vaccine, the study cannot cement causality or predict the vaccine’s effect on menstruating people, Lee said.
But it does add to the existing research on the potential link between the COVID-19 vaccine and changes to a person’s menstrual flow as well as reproductive history, hormonal status and demographics.
“We’d love to see future vaccine testing protocols incorporate questions about menstruation that go beyond screening for pregnancy,” Lee said. “Menstruation is a regular process that responds to all kinds of immune and energetic stressors, and people notice changes to their bleeding patterns, yet we don’t tend to talk about it publicly.”