COVID-19 Vaccines Can Affect Menstrual Cycle, Researchers Find

Researchers said the timing of COVID-19 vaccines can cause those changes.

A woman closes her eyes after receiving a COVID-19 vaccine at Sydney Road Family Medical Practice in Balgowlah, in Sydney, Australia, on Jan. 10, 2022. Jenny Evans/Getty Images

Researchers confirmed that COVID-19 vaccines are linked to changes in the menstrual cycle, according to a study published in March.

Published in the Obstetrics & Gynecology journal on March 1, Oregon Health & Science University researchers found that women who received a COVID-19 shot in the first half of their menstrual cycle are more likely to receive cycle length changes than those who received the vaccine in the second half.