Do COVID vaccines affect the menstrual cycle? Soon after shots first started getting into arms, anecdotal reports began to surface suggesting that the vaccines were changing people’s periods. Many said their cycles were arriving earlier and bringing heavier bleeding and greater pain after receiving a COVID vaccine.
Now, a new Boston University School of Public Health–led study has found that the vaccines are likely not to blame for any major changes to the menstrual cycle; any changes people did notice were likely the result of their body’s immune system responding to the vaccine. The findings were published in the medical journal Vaccine.
