SEATTLE — A lot of women have said their menstrual cycle changed after receiving the COVID-19 vaccine, but is there actually any relationship between the two?
To verify and answer the burgeoning question, we consulted with Dr. Lora Shahine, an endocrinologist and fertility specialist who is also an associate professor at the University of Washington.
"I have read the social media posts," Shahine told KING 5. "I have had some patients that have asked me and said, 'my cycles are a little bit heavier, or a little bit off schedule after the vaccine.’"
Stories in the New York Times and Chicago Tribune have helped fuel the fire online, but as the doctor who co-authored the op-ed in the New York Times wrote: “So far, there’s no data linking the vaccines to changes in menstruation.”
Still, when a researcher seeking participants for a definitive study tweeted about the topic, it got hundreds of responses, with many women saying they were late.
But doctors said menstrual cycles can change for numerous reasons, including diet, exercise, illness and more. The Mayo Clinic lists additional possibilities, including pregnancy, breastfeeding and premature ovarian failure.
"It's OK to be concerned, to ask questions, but it's not unusual to have a cycle that's disrupted or a little bit heavier,” said Shahine. “There are so many things that have to communicate, as far as hormones and our immune system, in order to have regular, predictable menstrual cycles. We can have a cycle thrown off by traveling or a really stressful event. So, I'm really not surprised that people are having a change after getting their vaccine. I don't want people to worry."
In other words, simply receiving the COVID-19 vaccine could be stressful enough to trigger a change in menstruation, even though the vaccine itself has nothing to do with it.
“I’ve been fighting the rumors that the COVID vaccine causes infertility for a few months now,” explained Shahine. “This is just the next rumor that we are going to fight and hopefully ease their worries, and help people get the vaccine to help us end this pandemic."
In the end, we can verify there is no proof that the COVID-19 vaccine affects menstrual cycles.