When adults gained access to COVID vaccines last year, most knew to expect headaches, fatigue and soreness as side effects.
But some researchers think it’s time to add another common one to the list: temporary menstrual changes.
An analysis published Friday in the journal Science Advances found that 42% of people with regular menstrual cycles said they bled more heavily than usual after vaccination. Meanwhile, 44% reported no change and around 14% reported a lighter period. Among nonmenstruating people — those post-menopause or who use certain long-term contraceptives, for example — the study suggests many experienced breakthrough or unexpected bleeding after their COVID shots.
The survey included over 39,000 people 18 to 80 years old who were fully vaccinated and had not contracted COVID. The study authors cautioned, though, that the percentages do not necessarily represent the rate of menstrual changes in the general population, since people who observed a difference were more likely to participate. The survey’s aim was simply to provide evidence for future studies, not to establish cause and effect.
Still, other recent research also found that the COVID vaccine is associated with a small change in menstrual cycle length.
The new survey started in April 2021, around the time people began to report unexpected bleeding and heavier flow post-vaccine. However, these anecdotes were at the time met with the rebuttal that there was no data linking menstrual changes to vaccination.
Read the full story at NBCNews.com.
