Wednesday, May 31, 2023


“You may choose to look the other way, but you can never say again that you did not know.”

— William Wilberforce

Women Report Menstrual Irregularities After COVID-19 Vaccination

menstrual cycles

From the start of the Emergency Use Authorization (EUA) vaccines rollout, many women around the world have expressed concerns about the effects of COVID-19 vaccines on the female reproductive system.1 Recently, women in the United States have reported changes in their menstrual cycles after getting an EUA COVID-19 vaccine.2 3  4

Clinical Trials Did not Study COVID-19 Vaccine Effects on Women’s Reproductive Systems

Women experiencing menstrual cycle irregularities have taken to social media platforms to discuss what has happened to them following one or two doses of the COVID-19 vaccine, raising questions about the vaccines’ safety. Clinical trials of experimental COVID-19 vaccines did not evaluate the effects on women’s reproductive health prior to the U.S. Food and Drug Administration granting a EUA to Pfizer and Moderna in December 2020 to distribute experimental mRNA Covid-19 vaccines in the U.S.

So far, there have been few official responses from the scientific community to the reports of menstrual cycle disruption following COVID-19 vaccinations due to lack of studies published in the medical literature,5 However, reportedly there are researchers at several universities now looking into the adverse event reports from women concerned about fertility and health of their reproductive systems.6 In the meantime, most physicians continue to express confidence in COVID-19 safety and urge women to get vaccinated.7

Some of the reports on social media include women experiencing menstruation earlier than expected, absent periods, longer periods, painful menstrual cycles, heavy bleeding with clots, bleeding in women who are post-menopausal and menstrual irregularities in women taking hormonal birth control prescriptions.8

Many vaccinated women experiencing irregularities in their menstrual cycles did not immediately associate it with the COVID-19 vaccine. Katy Fyksen had unusually heavy menstruation a few days after she received her second dose of the Moderna COVID-19 vaccine but did not make an immediate connection to the vaccine she had recently received.9

A 43-year-old woman, who had not had a menstrual cycle in over a year and a half due to an intrauterine device (IUD) that prevents menstruation, suddenly experienced vaginal bleeding after vaccination. She said, “I didn’t really think that it was anything until I saw that someone had said that, that it might’ve been a symptom or a side effect of the vaccine. It was like, ‘Oh, that’s interesting’”10

Scientists Speculate About COVID-19 Vaccine-Induced Inflammation and Menstrual Irregularities

In response to the reports of women experiencing unusual menstruation cycle changes, scientists and physicians have said that there is not enough scientific evidence to show that the COVID-19 vaccine itself impacts menstruation; however, experts are proposing biological mechanism hypotheses to explain why and how the vaccines could be affecting menstruation.11

Akshat Jain, MD, a hematologist at Loma Linda University School of Medicine offered his incite stating:

Inflammatory reaction has been noticed with the COVID vaccine. We know that because many, including myself after the second vaccine, developed some mild flu like symptoms. That inflammation, has a potential or potentially can modulate estrogen response, which could be the link between certain women having heavy periods after the vaccine.”12

While scientists investigate, Dr. Jain recommends that women who experience heavy abnormal bleeding should seek medical attention from their doctor to get a blood count and estrogen test.13

Obstetrician Comments on Knowledge Gaps in Clinical Trials of COVID-19 Vaccines

Heather Huddleston, MD, an obstetrician-gynecologist (OB-GYN) that specializes in reproductive endocrinology at University of California, San Francisco says that vaccine makers should have collected data about menstrual cycles during the randomized trials.14 She states:

There’s a long history of us not doing a great job at studying women in research studies because of some of this complexity The train sort of left the station on that because we are now recommending the vaccine for everybody. So it will be very hard for us to generate a control group to answer this question.15

Scientists Study the Association Between COVID-19 Vaccines and Menstruation

Two scientists working at Washington University and University of Illinois, who themselves experienced irregular menstrual cycles following COVID-19 vaccination, decided that the issue deserved more attention and began collecting and examining anecdotal data on women’s menstruation experiences after COVID-19 vaccination with the aim of facilitating further research.16

None of the clinical trials for the COVID-19 vaccines being distributed in the U.S. under an EUA examined changes in menstruation as a potential adverse effect.17 The U.S. Centers for Disease Control and Prevention (CDC) does not list it as a potential side effect of the vaccine either.18

Katharine Lee, PhD, a postdoctoral scholar in the Washington University School of Medicine Division of Public Health Sciences and her dissertation advisor Kate Clancy, PhD, an associate professor of Anthropology at the University of Illinois in Urbana-Champaign, who has studied menstruation in different contexts, designed an exploratory survey to collect data on women’s menstruation experiences after COVID-19 vaccination.19

Any menstruating or formerly menstruating woman, regardless of whether they had any irregularities, can sign up and report what they experience following any dose of any of the vaccines. Over 13,000 women have responded to the survey.20

Dr. Lee said:

If this isn’t something that’s specifically asked about, then people aren’t going to think to report it necessarily. It does seem like it should be part of the standard set of questions we ask when we’re testing vaccines in healthy adults. For me, it comes down to making sure that people who might experience menstrual bleeding after the vaccine know that it might occur after the vaccine, especially if they are perimenopausal or on hormone suppressing medication.21

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Click here to view References:

1 News Staff. Can the COVID-19 vaccine affect women’s menstrual cycles? Here’s what we know. WSOCTV May. 3, 2021.
2 Miller K. Can the COVID Vaccine Affect Your Period? Some Women Say It’s Changed Theirs – Here’s what We Know Right Now. Health Apr. 6, 2021.
3 Stern C. Women say they are having heavier and more painful PERIODS since getting their COVID-19 vaccines – as several claim it has also messed up their monthly cycle. Daily Mail Apr. 7, 2021.
4 Matsuzawa S. Can the COVID-19 vaccine cause changes in a woman’s menstrual cycle? KTVB May. 2, 2021.
5 Amitage M. Is the COVID-19 Vaccine Affecting My Period?  GoodRX Apr. 29, 2021.
6 Associated Press. Researchers Studying whether COVID-19 vaccines affect women’s periods after anecdotal reports of irregular bleeding. KTLA May 7, 2021.
7 Larsen K. Reports of menstrual cycle changes after COVID vaccine highlight issues with clinical trials. ABC7 Apr. 28, 2021.
8 Cox C. There’s no solid evidence COVID-19 vaccines cause menstrual cycle changes. That doesn’t mean it’s impossible. Insider Apr. 21, 2021.
9 Stock N. Some people are reporting abnormal periods after a COVID-19 vaccine. U. of I. professor is looking for answers. Chicago Tribune Apr. 20, 2021.
10 Ibid.
11 Cox C. There’s no solid evidence COVID-19 vaccines cause menstrual cycle changes. That doesn’t mean it’s impossible. Insider Apr. 21, 2021.
12 Larsen K. Reports of menstrual cycle changes after COVID vaccine highlight issues with clinical trials. ABC7 News Apr. 28, 2021.
13 Ibid.
14 Ibid.
15 Ibid.
16 Haelle T. Lack of Data on Covid-19 Vaccines and Periods Inspired Two Feminist Scientists to Learn More. Elemental.Medium Apr. 13, 2021.
17 Ibid.
18 U.S. Centers for Disease Control & Prevention. Possible Side Effects After Getting a COVID-19 Vaccine. Mar. 16, 2021.
19 Haelle T. Lack of Data on Covid-19 Vaccines and Periods Inspired Two Feminist Scientists to Learn More. Elemental.Medium Apr. 13, 2021.
20 Ibid.
21 Ibid.

21 Responses

  1. This situation is also occurring in women who have not received a COVID inoculation, but have been in close proximity to workmates or family members who have been inoculated. Also, pregnant women are having miscarriages who have not received a shot, but have been exposed to those who have received a shot. This goes beyond horrifying. This is evil!

  2. I got an early period right after my coworkers got vaccinated, and then I read that nearby people are receiving secondhand vaccine products that are being shedded by those who are vaccinated. I wasn’t vaccinated myself. My period is always regular, and I was mystified as to what triggered it to come early.

  3. Is anyone noting or hearing that women who have not been vaccinated, but spend time with people who have, are having changes in their menstrual cycle, including absent mensuration for multiple months? Anecdotally I am hearing about this, but would like to know more.

  4. None of those “vaccines” was studied long enough to have connected menstrual irregularities associated with it, or any other “irregularities”; the political push for this was just too great.

  5. What about the trend that non-vaccinated women are also experiencing irregularities after being around others that are vaccinated? Shedding? Phermones synching up?

  6. I am very glad this is starting to surface and that some scientists are starting to research the issue. Although I personnally have not been affected, I supposed because I have completed menopause, I can report here that it seems to go beyond just females being vaccinated to extent to females being exposed to people being vaccinated. My daughter and many of her friends, age span 20 to 30+ years old, have all been experiencing unusual irregular period, heavy menstruation and/or painful menstruation by being exposed to people who are vaccinated. Most of them work in retail/restaurant and none of them have been vaccinated. Can they participate in the study started by Katherine Lee and her advisor?

    1. There are menopausal women who are having periods also. I haven’t had a period in over a decade due to a medication that screwed up my system. Early menopause starred years ago including the dreaded hot flashes. That had stopped last year. A month ago I began having them, especially at night waking me up. I found out last week my son & his wife had the shot and between the time I began having the flashes and the present I have been in close proximity to them 3 times. There is a connection.

      1. thanks for sharing Redpill, and now that you mention the recurrence of hot flashes, it seems that I am having some similar issues with those resurfacing after I thought I had that pretty much under control. I did not make the connection until I read your post as I live in Florida and it is already real hot so it is sometimes hard to sort out if I get hot because of the sun or something else.
        with all that said, I am still much more concerned about younger women, including my daughter, who are experiencing very weird symptoms with their cycles from being exposed to vaccinated people.

  7. I have experienced menstrual cycle irregularities following the second dose of the COVID-19 vaccine. Endured painful menstrual cycles that included heavy bleeding with clots and bleeding 10 years after an endometrial ablation.

  8. What I find most disturbing is that pregnant women are given the vaccines. In our current culture, a pregnant woman is not even supposed to smoke or drink alcohol because it could harm the unborn child. There have been miscarriages among women who were pregnant and received a Covid vaccine. Even in 2009, there were miscarriages among pregnant women who were given the H1N1 vaccine.

  9. It’s good to see doctors beginning to examine the connection between the shot and the irregular menses.

  10. My step daughter who is 20 Has not received the Covid vaccine. But is an assistant coach this summer coaching over 20 girls have all received the vaccine for soccer. Her period has been going for over 25 days straight and she’s always been completely regular. Her period has been painful and heavy because she’s hanging out with girls that are vaccinated. Crimes against humanity

  11. I have been in menopause for 1year and a half….I started having a period….had a scan,an pelvic MRI and a DNC and nothing was found.I DID NOT HAVE THE VACCINE but was in the presence of someone that was recently vaccinated.i live in Ireland.

  12. Me too! odd menstrual issues. And I had 3 unexplained bruises, and an unexplained swollen ankle. I have not taken shot. but my 2 coworkers did, and most of my clients-I’m a hair stylist so I am in close contact with clients doing their hair. I just dont even know what to do now!

  13. I had a neighbor tell her story to me about her aunt who is in her early 80’s. Was very robust and healthy up until her second Covid shot. She then had trouble breathing, went to the hospital came home with oxygen. She also started to bleed vaginally. Unfortunately, she ended up dying within a couple days of all this.

    1. I’m happy for you but don’t be dismissive of those who are experiencing problematic bleeding issues. It’s frightening. Especially to those women who have already gone through menopause.

  14. I started having horrific cramps after spending in the evening with someone who has had the double Pfizer. I came on my period 12 days early and it was so heavy o was scared! I have been like clockwork for over 20 years!!

  15. Thought I got covid early 2020, now after being exposed to a person who got 3 doses of the shot, I am terribly ill with covid..I’m usually very healthy.. Is this from virus shedding?? Who has a good article on this?

  16. I have not had a period in eighteen years and now after my second pfizer vaccine I have had two weeks of intermittent heavy bleeding. I’m awaiting an appt with a gynecologist.

  17. My cycle has been bizarre the past three months. This month it came so early and I had cramps for two days straight. I haven’t had bad cramps in almost two decades. The blood is thick with lots of clots and doesn’t flow much the first few days. Then it flows really heavy for two days. That is not my norm at all – normally it starts out light on day one, then I have a medium flow for two days and by day four it goes back to light and starts to tapers off.

    There is definitely something being shed by the vaccinated. I have spent lots of time around recently vaccinated people.

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