• Kat J. McAlpine

    Editor, The Brink Twitter Profile

    Kat J McAlpine

    Kat J. McAlpine is editor of The Brink, Boston University’s news site for scientific breakthroughs and pioneering research. Kat has been telling science stories for over a decade, and prior to joining BU’s editorial staff, publicized research at Boston Children’s Hospital, Harvard University’s Wyss Institute for Biologically Inspired Engineering, and the University of Connecticut’s School of Engineering. Profile

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There are 64 comments on Do COVID Vaccines Affect Menstruation?

  1. I am 46 years old. I had the J&J vaccine end of April 2021. My monthly cycles for the first time in my life have become more painful and heavier each month. I plan to follow-up with my Doctor today. I am a nurse. I would be interested in providing my own personal experience to this study.

    1. I am 51 and always had a regular period. Had my 1st vax on July 23rd and 2nd on August 13. I haven’t had a period since July – I am now 40 days late. I no longer have hot flashes either. All my premenopausal symptoms are gone.

    2. I am also 46 years old and after my first shot had an extremely heavy cycle. After my second shot I got my cycle on 8/10 it ended and again on 8/31 and had it for 12 days. Stopped for 2 days and now spotting again. Have an appt in two days. I’m concerned.

  2. I’m 18 and I’ve had PCOS my whole life but my cycles have always been pretty much on time and I’ve always been lucky not to be a bad cramped. . Ever since I got the vaccine my cycles have been either very late or very early, cramping, Basically just spotting some months while others very heavy (much more than ever before). The only thing in my life that changed was the vaccine. (Moderna)

    1. I am 49 and I was having my period when I received the 2nd dose and prior to receiving that 2nd I felt extremely ill from I assume my period. Since that 2nd dose in May my cycle is all over the place and a couple of times it has been just spotting, when normally it is very heavy day 1 and then lighter for days 2-4. It is definitely very different. I had Moderna. Happy to participate as well.

  3. Glad research will be done. Don’t like that the driving goal of NIH is to “reduce vaccine hesitancy” rather then simply making sure some negative or unintended effect isn’t really happening. Please take extra efforts to be eliminate biases! Too many past cases of women / children suffering bad effects of medical treatments… DES, Thalidomide, etc.

  4. I thought I’d had a miscarriage. Obviously I was wrong, it was just a clot but I’ve never been pregnant, never had such heavy bleeding and never seen a clot like that. I’m 41. It started after the 2nd Moderna shot and hasn’t stopped, every cycle for 4 months now. No other health problems, before or since. I submitted a VAERS form.

  5. “There was an urgency to it, the fact that this was getting so much attention. We were worried this was contributing to vaccine hesitancy in reproductive-age women,” They are more worried about vaccine hesitancy than the reproductive health of women. Can we expect this bias to shine through when the results will be published?

  6. I received my 1st dose August 11th and noticed clotting during my menstrual which arrived on time that month. I didnt think anything of this. Having my 2nd dose of Moderna on 9/8 and now on 9/10 I began menstruating and my cycle was not scheduled for two more weeks in frustrating! Ii literally had my menstrual about 10 days ago! I am a healthy 35 yr old woman who does not regularly take medication nor have any health concerns. There have not been any changes in my eating or activity habits nor personal stressors that can contribute to such a change. Immediately I knew it was due to this vaccine and more people should be able to report this. Many articles I have read take this side effect as a joke.

  7. I’ve had the Moderna vaccine. It has changed my cycle. Growing up my cycle has never been regular and very heavy and painful. I had the NovaSure surgery, which eased up the heavy flow and some cramping. The Moderna vaccine has reversed what was done.

  8. I am a CRNA and hear all kinds of stories regarding how the Covid vaccine has changed women’s menstrual cycles. People have told me they have come out of menopause after receiving the vaccine. Apparently my 72 year old neighbor started her cycle again per her GYN. This is mind boggling. This is also the primary reason I have not been vaccinated nor will I let my daughters get vaccinated (ages 11 and 13). I can’t wait to see the results of your study! Thank you for paying attention to this very important subject!

  9. Prior to the vaccine, I was happy that my periods were getting lighter and lighter and fewer days in total. Now that I have had both shots it seems my periods are much more heavier than they used to be. This is the second cycle since the vaccination experiencing these heavier periods.

  10. Iam 39 years old. My periods used to be very regular. Exactly 28 days. After Moderna vaccine, my periods have become irregular and getting 1 week to 5 days earlier.

  11. After my second dose my cycle has been off. I have had a period since July 11,2021. I went the doctor who put me on birth control which has not helped. I have a light period with some cramps. I just want to know when will this stop.

  12. I am having severe cramps and much heavier periods since vaccine to a point I cant go anywhere during first few days and plan on going to see a doctor since it’s been more than 3 months since 2nd shot now. I also see a lot of clots being passed and period is so heavy I have to change Super tampon every 2 hours first 2 days and also wear tampon under and cant do much 2 days with loss of blood and fatigue.
    I plan on going to see a doctor and get ultrasound done, I have never been pregnant and my period has been regular had bad cramps before but this is severe bleeding and clots.

  13. Hi, I have irregular periods. I got the Moderna vaccine on August 30th & the 2nd dose Sept 2nd. I got my period very bad & painful right now on Sept 12th. Usually my periods are spiradic & random but now this is my 2nd period in one month & more painful then ever. Usually I get good period & then next painful excruciating period. Now they’re all bad & painful. I’ve never had 2 in one month before. They’ve only been random like for example 1 in Aug then 1 in Oct. so yes irregular & random. But these are so painful it’s uncomfortable & miserable and I’m crying. Also Im a trans man so you see why this is more overwhelming & painful to experience ;0(

  14. I am glad someone is finally looking into this. A lot of people were told that if they did not take the vaccine they could not attend classes or go to work. Institutions without knowing how the vaccine affects women decided that their bodies and fertility do not matter. I would go further to say that the reward outweighed the risk when implementing these decisions mostly because the risks are seriously understudied.

  15. A lot of misinformation in the comments. The vaccine always makes things better, and I am sure this study will support this fundamental truth once all the data are collected and properly analyzed. If not, how about, it would be much worse if you got Covid without the vaccine. There is always a positive answer if you need to find one.

    1. Are you crazy??? You probably high on something or never experienced what every woman in this forum experienced. I also experienced what they called breakthrough bleeding/uterus bleeding and huge clots, sharp abdominal pain (I felt like my uterus was about to expel out of my body, that’s how painful was) and diarrhea, with the first dose of Pfizer. I reported directly to Pfizer and they never responded. Unfortunately, and is in the history around the world that women matters are not important, or just delusional. Example: Tampax and their supper tampon/Toxic shock syndrome. It took many years and a lot of courage women to put Tampax on blast, until they recognized their product was dangerous, and it was FDA approved. I recommend and encourage every woman in this forum not to only give your information to the NHI but report this, first to the provider who gave you the vaccine, then VAERS, and Pfizer. They need to do something about this and if they want to stop hesitance, be serious do studies and improve Moderna and Pfizer. I still not taking the second dose because there was a case of a woman that had Pfizer second dose and bleed so much that her hemoglobin went down to the point that she needed Iron pills, and also hormone treatment, a woman that had regular periods and never an issue.

  16. I am 32, I got my first dose of Pfizer September 2nd,2021. My cycle was normally 28 days. My period came on day 33, heavier than usual, with lots of clots and the blood has been dark red the entire time. I get my period every month and on time before the shot. Now, I am on day 5 and the flow is as of I am on day 2 of the cycle. Which is odd because on day 5 there’s usually nothing or a small amount.

    1. I received the Moderna shot and was due to have my period a week later. I got it 4 days early. I am a 36 year old woman who has a very regular and consistent 28 day cycle. After the vaccine it was slightly heavier and longer than usual. This month my period was a whole week early.

  17. I got the modena vaccine and had a very late period, same with my twin sister. It’s a bit of a shame that this wasn’t studied as a possible side effect to the vaccine and women were not aware ahead of time. Many of us hate our periods but it’s very much tied to our health as women so its concerning when things like this happen.

  18. I have had an IUD for 7+ years so very rarely do I even get my period at this point. After my two shots (Pfizer), I spotted a little more than normal but nothing since. My two girls (18 and 16) were a little off cycle after the shot but seem to be back on track. They had cramping before the shot and have it after so hard to know if the vaccine affected them in that regard.

    1. I have the Mirena IUD (with hormones) and prior to getting the Pfizer vaccine I had little to no spotting occasionally. Since getting vaccinated in April, I’ve been having a much heavier cycle. Not great, but also better than having Covid.

  19. I had never heard of this, but thinking back on my own experience I wonder if there is a link. I have always had PCOS and when not on birth control might get my period once or twice in a year. I had to go to an infertility specialist to conceive my daughter using letrozole. I gave birth in October 2020 and was vaccinated in April 2021. The next month my period returned and while the cycle length can vary by up to 6 days it has come every month. I figured it had to do with hormones changing after having a baby and never considered a link to the vaccine, but will be interested to see what this study finds.

  20. I’m glad that research is being done on this and that the anecdotal evidence of thousands (millions?) of women is not being ignored or glossed over (as it was in BUs webinar on vaccines in the spring). However, like others, I am concerned that the evident bias shown at the outset of this research will impact the outcome. Really hoping that is not the case and that the actual truth of whether or not these vaccines impact women’s reproductive health is the ultimate goal of conducting this research, not just reducing vaccine hesitancy.

  21. I’m glad to see this issue being studied and agree that menstrual health and the well-being of people who menstruate has been seriously neglected. I was also glad to see that Diana Bianchi of the NIH, quoted here, used “people who menstruate” phrasing when discussing this research. However, I was disappointed that BU Today did not follow her lead, despite today’s publication of the POV pointing out the importance of using gender-inclusive language in coverage of abortion rights. The same people who have a uterus and can become pregnant also menstruate. These include many but not all cisgender women, some intersex people, some gender non-binary people, and some trans men. In 2021, we simply cannot assume that knowing someone’s gender identity tells us what bodily organs they possess, or that knowing what organs someone has is sufficient to accurately know their gender.
    To the reporters and editors of BU Today, I believe you can do better than this. Our university community includes increasing numbers of people who are linguistically erased and excluded by the cis-normative, gender-binary framing of socially and medically important issues — despite the fact that these issues pertain directly to their bodies. Institutionally and through the hard work of many faculty, staff, and students, BU is making large efforts, investments, and progress to become more inclusive. Please help us.

    1. Karen, thank you for your comment and submitting this powerful, I am glad we were able to publish it, and welcome more ideas and pieces like this to further this discussion. Doug Most

  22. Uh are these comments generated by robots? Most of them have glaring grammatical issues I wouldn’t expect from actual people. Also everyone-the vaccine is fine.

  23. My 12yo received her first dose of the Pfizer vaccine and had spotting the same day. She had only had one episode of spotting 8 months previous. We mentioned it at her well child visit in August but her doctor didn’t know of any connection.

  24. I am perimenopausal and my cycles have become very long. I had a normal period the month before my first dose of Pfizer and it had been 126 days since my last one. After getting the first dose I had a very heavy period with large clots 21 days after the start of the one prior.

  25. Pfizer dose 1 was received 3/18 and my cycle was due any day. It ended up being 4-5 days later than normal. Dose 2 was 4/8 and I didn’t have another cycle until May 14th skipping April all together but a little earlier than what I would have expected in May. I think the timing issue is real, but I haven’t experienced long-term effects on my cycle. I would make the same decision to receive the vaccine as early as I was allowed over and over. I’m so grateful to the science community.

  26. By the 2nd day of my first Pfizer shot I got my period 2 weeks early. More painful and heavier than usual. I let my doctor know right away, but she said it had nothing to do with the vaccine. I got my second shot 4 weeks after and exactly the same thing happened. And now I’m having irregular bleeding in between periods. I really hope there’s nothing more to it than a normal immune system response to the vaccine. Anyways I think it took them to long to take this seriously and try to find out what’s really happening.

  27. 25 years old with no prior health concerns. 28 day regular cycle. My cycle has been 18-22 days since my second COVID shot 6 months ago. I’ve experienced heart palpitations and extremely painful and very oddly short periods. No one will listen to me or help me. I’ve been told it’s just anxiety over and over again and it’s horrible. Doing everything I can to help my body heal.

    I would love to participate in this study. Please connect me.

  28. I am 31 and got my second vaccine yesterday and woke up the next morning to spotting and cramping. I have the nexplanon implant and don’t usually get a period or experience any cramping. There is no mistaking that my menstrual cycle was affected by the vaccine.

  29. I would be curious if any of these women had the actual virus prior to receiving the vaccine. Wondering if the link is with the virus??? I have not been vaccinated yet, but am 99% sure I have COVID in February 2020. I’m 42 years old and for the first time in my life had an abnormal period that lasted 22 days, stopped for 8 days, then started again for 9 days with excruciating pain and excessive bleeding with half dollar sized clots or more. I had a checkup and they determined my uterus to be enlarged and ordered an ultrasound. The ultrasound and Pap smear, both came back clear. I would also be willing to participate in this study.

  30. I received the Moderna in March of this year. I had no idea about the effects of the vaccine on menstrual cycles- but I now join many of you who have experienced changes. My cycle has not been as consistent- coming a day of two earlier or later than expected. I also haven’t had cramps since I was 14 years old. I am now 44 years old and have experienced cramping. I am praying that this is temporary and not indicative of future issues with this vaccine because my daughters (13 and 18) were vaccinated earlier this month. Frightening to say the least- but what is even more frightening is the thought of them being taken out by COVID.

  31. I’m 43 and I had Moderna vaccine in May and my cycle has been heavier and painful. I didn’t have cramps prior to the vaccine. My daughter is 13 and has complained about the pain as well. She had the Pfizer vaccine. I am interested in the study.

  32. I am 48 and just had my first dose of Pfizer vaccine two days ago on 9/12/21. On 9/13 I woke up in the middle of the night gushing blood. Not to be graphic but it was so bad you would have thought someone was seriously injured. I have been bleeding so heavy, having large blood clots, and having to change a super plus tampon every 30 minutes. This is not normal for me at all. I have terrible cramps and feel exhausted. I had no idea that this was a side effect or possible side effect of the vaccine. This needs to be talked about. More women need to know that this could happen to them. I was forced to get this vaccine or lose my job. I was concerned that this vaccine was distributed too soon to the public to be safe. Women need to know what they are signing up for!

    1. I’m with you! I will be part of the new mandate and lose my job as well if I don’t get the vaccine, unless my state is able to block the mandate. It’s honestly stressing me out to hear women are having these issues, because I’m currently experiencing these issues (abnormal heavy bleeding, extremely large clots and severe pain for extended period of time) without having received the vaccine.

  33. I received J&J in April and my periods have always been relatively light. I never had COVID that I was aware of. The cycle remains the same every 27 days but I have noticed I’m getting more and more severe cramps. This last one I am going through now literally has my stomach completely bloated and I’m holding my stomach in pain. I can’t sleep because it’s so uncomfortable and Tylenol does not help much. I had no idea the vaccine could do this until I did a search and found this article.

  34. I am 36yrs old. Very regular periods lasting 5-7 days for years. After first dose of Pfizer on Aug. 31st I noticed spotting same day and I wasn’t due for my menstrual cycle until the second week of September. Next day after vaccine I started bleeding very heavily and passing blood clots ever since. That makes it 15 days now and doesn’t seem to be getting any lighter. I have horrible cramps and horrible headaches. I feel tired and weak all day long. My second vaccine is due September 28 which I’m definitely not getting. I’m afraid it might make my bleeding worse or extend it even longer. I so regret even getting the first dose.

  35. I had my second dose of Moderna in April. I’m 31 and have a Mirena IUD, which has kept my periods so light I didn’t even notice them. In the past few months my body has reverted back to pre-IUD days. I had to start buying tampons again, I have cramping again, I have multiple days of symptoms. I thought maybe my IUD shifted or something, but now I realize it lines up perfectly with the vaccine. I cannot imagine the burden of this for women who already had heavy or difficult periods.

  36. My period is very heavy, clots, very painful cramps and leg pains for the first three days. This was my first period after the second dose (moderna). I am 53 with normal periods without pain before the shot. Something is different for sure.

  37. I had the first dose of Moderna about 26 days ago, I’m 44. I have had regular clockwork periods since I was 13. 3 days of heavy. 2 days of light. 5 days total, all my life. Now, this past period after my first dose, I bleed heavy for 4 days, then light for 2, and spotting light blood now, for 10 days! I am concerned. But what do I do?? Not sure, and I’m due for my next covid shot in a few days :(

  38. Wow I can’t believe this is a huge issue and there is barely any news regarding women’s cycles being affected. Thank you BU for publishing this and following the research! I am 28 from Canada and received both shots of Pfizer vaccine last one Aug 8. I was diagnosed pcos in my early 20’s and been battling irregular periods most of my life but being off BC since I was 22. Been fairly consistent with the odd cycle maybe lasting 3 weeks if I skipped a month. Since having my second dose (I was mid cycle at the time) I had heavier flow for the next week which started slowing then had spotting for a couple days but thought not much of it. Then out of no where had heavy bleeding the next week and hasn’t stopped bleeding since. Flow has levelled out but have been going for about 8 weeks now total cycle. You bet I am doing a crazy amount of research. Would hate to have anyone else go through this and would have most definitely thought twice if the vaccine had more research based on women’s health.

  39. My closest friend of 56 years old have not had her menstruation since the last four years ( menopause). A month after the second dose of Moderna, she started bleeding for 3 weeks now. Before the vaccines she was healthy no problems. She has to go to the the hospital because the bleeding was too strong. Doctors are doing a series of tests but they have never mentionned a potential adverse effect of the vaccine.

  40. I’m 47 and my period has been regular my entire life. So much so that I got pregnant on the first try both times. After I was vaccinated with Moderna, I had two periods in one month, the next month was longer and heavier, then I was 2 weeks late. My periods are all over the place. I’m convinced it was the vaccine. This should have come out in the studies and it’s frustrating that this wasn’t studied and listed as a side effect. How is this missed; seems very prevalent.

  41. I am 42, always been very regular. I have not taken the jab and yet I’m experiencing the same things vaccinated women are sharing. So are others I’ve spoken to. There is obviously something to all this, yet the articles I read claim we all must be stressed and simply need to take better care of ourselves through diet, exercise, etc. Maddening. I hope their research brings about Truth, but I don’t have much faith in it.

  42. I’m glad BU is finally opening up to an alternate discussion on vaccines, not just the ‘safe and effective’ rhetoric that glosses over these things.

    It deeply saddens me to see so many people commenting that they wish they had known this was a possible side-effect BEFORE getting the vaccine, because of course – of course! – they should have been able to know this, but over recent years (and especially over recent months) anything that dares to question the safety or efficacy of vaccines is simply labeled as “misinformation”, and is taken down/censored, ridiculed, or the authors/researchers are discredited as people who are simply looking to make money from their articles and events (yet ironically, no-one ever comments on how big pharma also have a very obvious financial incentive to push the vaccine narrative). Everyone should have a right to know what will happen to them if they opt for this vaccine or any other.

    So my plea to anyone who might read this is this: let’s open up conversation about these issues. Let’s allow for viewpoints that contradict the mainstream, because that’s how discoveries and advances are made. Let’s not ridicule those who choose not to get a vaccine, but rather, listen to what their concerns are. Let’s be open to learning from one another.

    There’s enough division in the world. In 2020 we were “all in this together”, but 2021 has been about tearing each other apart for believing in different things. People are allowed to have different perspectives. Let’s try and embrace that and create a more positive culture around these differences, rather than engage in the shaming, ridicule and blame that has prevailed lately.

  43. I’m 39 and have had periods like clockwork all my life until recently. Two months after taking the second dose of covid vaccine, my periods are totally out of whack!! My periods usually last 4-5 days but this time around, I only had them for two days. Then they stopped but I’m feeling period-like cramps ALL THE TIME!

    Another thing that has totally freaked me out is the pain in my right breast and armpit. I have a few fibroadenomas in my right breast that have suddenly started hurting a lot. I have scheduled an ultrasound mammogram for next week. To say the last few weeks have been stressful is an understatement. Someone needs to give us answers!!!

  44. I’m 47 no family history with any female issues. I never had bad or irregular periods. I never had real bad cramping or large clots with my periods. I had 4 normal pregnancies and PAP tests with zero issues. I received the Pfizer shots and now having all on these issues now. Had to cancel my PAP test 2 times. When I finally got it done. My Dr. looked at me with fear and seemed to be afraid to do my PAP. Stated I was completely inflamed. I had a health heart scan a month before covid that came back great but I also now having chest pressure and pains after the vaccine. I have to go get a ultrasound and blood work for my pelvic to see whats going on. Then see a heart Dr. to check me. I am outraged they are mandating this for everyone. I work in a hospital and my own bosses don’t care about my health. The town hall meeting we had they don’t want to hear it. I also learned that many others are having the same health issues and our hospital whats us to just be quiet. Now my boss questioned me why I went to the meeting and told me I need to watch what I say. I feel my job could be in danger. I no longer have faith in the hospital I work at because they also stated they are only using Remdisivir and no Dr’s are allowed to give any patient anything else for covid. Doing research on that med. and found out it causes kidney failure and more. It even was taken out of a study because of deaths. We need to start researching and not just take what anyone says. I found Dr Bryan Ardis on Rumble very interesting and also Jesse Ventura in 2009 interviewed a Scientist that stated all this will happen.

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