A new study has indicated that some COVID-19 vaccines may affect the length of a woman’s menstruation.
The research found that after getting a dose of the COVID-19 vaccine, some women’s menstrual cycles increased by one day longer than usual.
They noted that the average increase in the length of the menstrual cycle appeared to be driven largely by women who received doses of either Pfizer/BioNTech or Moderna within one menstrual cycle.
As reported by CNN, the researchers added that for this group of women, cycle length increased by an average of about two days. But the change was only temporary and resolved within a couple of months.
The study was conducted in the US and saw researchers collecting menstrual cycle data of women between October 2020 and September 2021 via a fertility-awareness app.