Myth or Fact: Women’s Menstrual Cycles Synchronize if They are in Close Proximity for Large Amounts of Time

menstrual-cycleDo women’s menstrual cycles sync up over time if they are in close proximity to each other? Being someone who lives with 4 girls and 1 other boy, this knowledge would be very beneficial. I feel like I should know if the estrogen ocean I’m swimming in will have very stormy seas every 28 days. The belief that this occurs is widely known. In 1999, one study reported that 80% of women believe this phenomenon occurs and 70% of them find it pleasant to have this be the case. The truth, like so many other things in science, is controversial. The main body of evidence, however, suggests this is nothing but a myth and it’s really just random chance when this synchronization is occurring. Let’s find out why.

A woman’s menstrual cycle is counted from the first day she begins menstrual bleeding until the first day of the next menstrual bleeding. This cycle can vary from 21-35 days, although the average is 28. It’s separated into 4 different phases- the menses, follicular, ovulation, and luteal phases.

The menses phase is when the woman is actually bleeding. The average time frame of this bleeding is 3-5 days, though 2-7 is considered normal. It’s this phase people are paying attention too when they talk about menstrual cycles synching up. They look at the first day of bleeding as the start point. The follicular phase is where the follicles in the ovaries begin to mature and form an egg. Simultaneously estrogen levels rise causing the lining of the uterus to thicken. Ovulation then occurs which releases the egg due to an increase in a hormone called the luteinizing hormone. The final phase is the luteal phase. The egg is released from the ovary and travels down the fallopian tubes and in to the uterus. If the egg is fertilized and attaches to the uterine wall, pregnancy begins. If not, estrogen and progesterone levels fall causing the thickened lining in the uterus to shed and menses begins again.

The entire process from the start of menses to the beginning of the next menses is mediated by hormones. Because of the hormone mediation, proponents of the synchronization theory claim that pheromones can affect hormone levels and thus, affect the cycle.

The theory began in 1971 when a psychology student at Harvard (Martha McClintock) published a paper in “Nature” stating that women who spend a lot of time together will tend to have their menstrual cycles synchronize over time. She theorized that pheromones affected the hormones of the women causing the synchronization. Pheromones affecting people in general is an extremely controversial scientific topic in and of itself. It would take an entire article to do it justice so I won’t be going into it here. That being said, in 1998, McClintock published another paper in “Nature” which found that if a woman was exposed to cotton pads soaked in the sweat of women in their follicular and luteal phases, the phases of their cycles were significantly altered.

The controversy lies in how you interpret the data from McClintock’s, and others, studies. The differing lengths of cycle times combined with a myriad of other things that affect cycles, causes the results to be simply a matter of chance. One researcher, H Clyde Wilson, outlined three serious errors involved in McClintock’s research. When you correct for these errors, the evidence for synchronization evaporates.

So why is this so complicated?  Defining what exactly synchronization in cycles is can be extremely difficult. While there are averages, most women tend to have their own unique cycle that can be affected by many things. Suppose you have one woman who has a 28 day cycle and one that has a 29 day cycle. If they both start menses at the same time this month, they will be off by one day on the following cycle and then 2 days on the one after that. Over time they will, once again, have a cycle that will coincide with one another. To take it one step further, let’s say you have women at both ends of the “normal” range for cycles. The first has a 21 day cycle and the other has a 35 day cycle. If the women who has a 35 day cycle starts on January 1st, and the women with a 21 day cycle starts on January 15th, both of their cycles will start approximately at the same time the next month (February 4 and February 5 respectively). Those two women could say “Wow, we were two weeks off last month and this month we have been spending a lot of time together and look, our periods are synchronized!”

Other things to consider when talking about cycle periods is that each individual has different patterns of normal. Some have regular patterns, some have variable patters, and others have regularly irregular patterns!  Those same women can also experience different cycle lengths and regularities depending on several environmental factors such as strenuous exercise, puberty and menopause, low body fat, and extreme weight loss or gain have all been shown to affect cycle lengths.  Due to the fact that hormones regulate the entire process, anything affecting hormone levels, will in turn, affect menstrual cycles.

Simply interpreting the data and not being cognizant to our “confirmation bias” (the tendency to search for or interpret information in a way that confirms one’s preconceptions) can lead to errors in statistical analysis.

Take for a specific example two subjects involved in a study that started on July 1st. Subject A with a 28 day cycle starts her menses on July 25th and then again on August 22nd.  Subject B, with a 30 day cycle, has her onset start on July 5th and then again on August 4th. If you believed in the “synchronization” theory and were not aware of your confirmation bias, you could look at these numbers and conclude their cycles were 20 days apart (July 25th and July 5th) in the beginning and are now 18 days apart at the second onset (August 4 and August 22). Thus the subjects are probably synchronizing. The truth is, the opposite is actually true, they are diverging not converging. Subject A would have had menses start on June 27th as well. Not looked at by this study starting on July 1st. That puts both subjects start as 8 days apart in the beginning (June 27 and July 5). The second cycle being July 25th and August 4th makes them 10 days apart and diverging. The exact opposite of the original conclusion.  So you can see from this how it would be easy for a study on this subject, if not performed correctly, to provide very wrong conclusions even without all the noise of things like regularly irregular periods and other factors effecting hormone levels.

The idea that synchronization is simply a matter of chance has been replicated by several other studies since McClintock’s “groundbreaking” conclusion in 1971. One of the most famous was done by Zhengwei Yang, of North Sichuan Medical College in China, and Jeffrey Schank, of UC Davis in 2006. They found women living in groups did not synchronize their cycles. They looked at and analyzed previous studies claiming synchronization occurs. After correcting for statistical errors, they showed those results were really at the level of chance. They went on to show that because of cycle variability, they produce convergences and divergences in menses onsets and this explains the perception of synchrony.

In the end, Michael Shermer in the book Don’t believe everything you think, said it best, “Smart people believe weird things because they are skilled at defending beliefs they arrived at for non-smart reasons.”

Whether you believe McClintock (the biggest proponents of synchronization out there, starting back from her days as a student) and say that your menses converging and diverging is a result of pheromones affecting your hormones, or you take a step back and look at the main body of research that gives a non-pheromone mediated reason for why the convergences and divergences happen, the result is the same. Due to the differences in female cycles, and the environmental factors that can affect them, there will inevitably be certain times when the women in your family will all be in their menses phase at the same time. I shudder to think! Father-son vacation anyone!

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Bonus Facts:

  • The average age a girl starts having menstrual periods is between 11 and 14. Beginning around the age of 39-51 a women will begin to have fewer menses. Both age ranges will tend to have cycles that change consistently or are longer. The teenager will experience her menses evening out and become consistent while the older women will have hers get longer and then stop. Either way, if I haven’t said it already, I’m glad I was born a man! You ladies get the short end of the stick when it comes to periods at least. 🙂
  • The first menstrual period of a girl is called menarche. The average age of menarche dropped from 12.75 to 12.54 years old from 1988-1994. This mirrored the results of other research that found the average age of menarche dropped 2 ½ months between 1963-1970. The authors of that research published their findings in the journal Pediatrics in 2003. They concluded that the decrease in menarche paralleled the increase in the body mass index of the US population, suggesting that higher relative weight was strongly associated with early onset of menarche.
  • In case you didn’t already know, the most common cause of a missed period is pregnancy.  Shocker!
  • As stated in the main body of this article, hormones mediate menstrual cycles. Progesterone and estrogen levels are one example of how hormone levels affect menses. Progesterone is secreted by empty egg follicles after ovulation. This causes the endometrium (the lining of the uterus) to secrete proteins to prepare it for fertilized egg implantation. It also helps in the growth and maintenance of the endometrium. Teens and women close to menopause have changing levels of progesterone and estrogen. The result is heavy menstrual bleeding and an increase in cycle length.
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55 comments

  • I was on a college summer leadership project for 7 weeks. We stayed in the same building (an old 1920’s hotel, girls on one floor, guys on the other – many to a room) worked and played together.
    Every week the guys & girls would have their own meeting times together.
    One of the girls told me about the last meeting in which the girls took a poll. Their periods were all occurring within a 3 day window.
    This was about 20 girls.

    • i didn’t read the article through. But if the Wemon were on birth control. That changes everything. Common sense would be to ask considering it is a huge hormonal “stabalizer” but im not on it. I’m in college. when my mom and i spent a lot of time together mine came right after hers. When she started working long hours. Hers flipped. but when i come back home from college and she spent time with me at night it started to lean toward her normal pattern. Though she was still working those hours.

  • Ok I dont want to sound creepy or weird. I will just tell you about my experience.
    I live with an adult woman and two female cats.
    I swear to god, before the cats were spayed, their monthly time when they got into heat always fell within the same time the female human in the house had her period.

    • Omg- thank you for sharing that. I hadn’t had a period in almost 2 years; went through the whole menopausal thing and everything. Then rescued 2 tiny female kittens, who always sleep on my lap. When they hit 3.5 months my period came back! 2 years without; I can only surmise that I picked up on their hormones or pheromones or whatever. I have no other explanation.

  • When I first started college one of my floor mates in my dorm told me that by the end of the year our periods would be completely synced up, and of course I was skeptical. It seemed highly unscientific and more like an urban myth. This article makes sense, because there were times when it seemed I was synced up with some girls. But it was really that throughout the month there was always someone on her period, so of course when my time came I was synced up with someone.

  • The synching of women’s menstrual cycles is attributed(anecdotally) as the reason for birth of the music style ragtime. In the days western expansion, as settlements became towns and then cities, services followed. Houses of prostitution provided on service. The synching of the ladies menstrual cycles meant that each month the house was effectively closed with nothing but the bar to bring in money. The piano player was relied upon to entertain the customers and thus the style became known as “ragtime”. Not scientific, but certainly a satisfying explanation.

  • Charlene A. Howell

    How is it that a man is allowed, with little question, to speak on this female issue that dates back to the days of creation? I’ve had my cycle for 20 yrs now, and have noticed that when I spend more than 3 weeks in close proximity of another woman or women and my cycle hasn’t already begun, it’s almost a guaranteed certainty that our cycles and premenstrual symptoms will synchronize. Weird but true…

    • Daven Hiskey

      @Charlene Howell: Because the man is a medical professional maybe? Or, let me put it this way, I’ve taken a crap literally thousands of times in my life, but that doesn’t make me an expert on the sphincter or the digestive tract. 😉

    • Agree with you 100% (and wth are those panty liners in the pic good for? LOL NOT anyone’s period, that’s for sure! 😀

    • How ignorant. What if I said a woman had no place sounding in on male health issues even if she’s a doctor?

  • THOUGH THE ARTICLE WAS GREAT (AS ALWAYS…..THANKS SCOTT) BUT THE END COMMENT OF DAVEN WAS THE WHOPPER. TNX FOR THAT ONE TOO (AMAZED AT YOUR QUALITY …..WHEN U STATE SUCH OBVIOUS FACTS….HOW CAN U STAND SUCH MORONS, DAVE ??).

  • 2 words: boot camp. Cycle “sync up” is irrefutable FACT!

  • I have 2 daughters, my period is always faithful and always came around the 25th so holidays 🙁 were no fun lol . Once my girls started my date kept changing and theirs too until now we all 3 start at the same time or within a day of one another ! When all of this started happening I was scared that something was wrong with me but that was all it was…we were syncing so I am 100% , without a shadow of doubt positive that this is real !!!! Now feel sorry for the 2 boys ( my husband and my son) ha !

  • Let me add that when I was a teen my step sis and I lived together off and on and EVERY time we started living together we would sync back up ! My Parents made it a running joke so believe what u will …it’s real !

  • why jesus fuck burger king. must you write this long text for you publisher, why can’t you just answer the question. YES OR NO?

  • Period synchronization is a fact! I am a female who seems to sync up with anyone who i spend quite a bit of time with. For example i lived with my mother and i noticed that we started within two days of each other. My cousin moved in and the next month my period (along with my mother) started the same exact day as hers. I gained a best friend in that time and noticed that within a month or two my period moved and started in the same week as hers. Then when i moved into a dorm my period did a complete 360. It MOVED from the end of the month to the middle. Which happened to be the same week as my roommate. I still have the same roommate (its been two years) and it has not changed. So the fact that you are writing about something you dont even experience, nor understand stuns me. Your just going off of what MALE scientist are saying. I feel i should tell you that science/studies cant explain everything.

  • Well it’s pretty common here. I have 4 sisters and a mom and I as well who are synced within the week. Actually me and my mom the same day every month. Doesn’t seem like a myth to me considering it happens every month. Every now and then I’ll stay with a friend who’s female and we’ll be synced within that week.

  • He’s not answering “yes” or “no,” and I don’t believe he was planning on giving a definitive answer. Instead, the author is saying that you can’t just believe a scientific study off the bat. Since menstrual synchrony is difficult to define, it’s going to be difficult to prove or disprove. He’s telling his readers to look for the errors and biases within a study and then to draw conclusions for ourselves. With this particular topic, you need to look at the sex of the researchers, a definition (if one is provided), as well as how the subjects were chosen and how the data was collected.

    Personally, I have experienced menstrual synchrony, thus I completely believe in its existence.

    • Once again, what the HELL does the sex of the researchers have to do with anything?

      Geezus, you people! Sexist much??

  • Bill Guy the science nye

    ITT: girls who don’t understand anecdotal evidence argue with scientists.

  • Bill go back to 4chan

    “Smart people believe weird things because they are skilled at defending beliefs they arrived at for non-smart reasons.”

    Women flood the comment section with examples of their periods synchronizing, and we say they’re wrong because we can point out some flaws in a scientific article from the 1970’s? That doesn’t seem so smart.

    If there was a preponderance of scientific evidence cited in this article I’d feel it was more credible. As it stands, I think it’s smarter to trust the women who have lived the “science.”

    • Bill’s point is that anecdotal evidence is one of the lowest levels of evidence in existence. This article is mainly written to say that there is no strong evidence and therefore we can’t assume to know.

  • As a retired teacher I can assure you that synchronization is a fact. You can ask any janitor.
    When school starts all girls have independent cycles and the sanitary napkin dispensers handle the load but by Halloween they are full 3 weeks and empty the fourth each month. Teachers have to keep a box of napkins for girls in her classes when the dispensers are empty.

  • I work in electronics, and have seem many times where flashing lights will appear to sync up for awhile and everyone notices… people comment on it. A while later when they no longer sync up, no one says a thing. If two woman have 7 day periods, one every 27 days and the other every 28 (or any other variation in time), they will sooner or later sync up for a while, then drift apart. It’s not the few times they sync up that shows proof of concept it’s that many times it doesn’t. Heck, otherwise most every woman on the planet would have their period the same time, as most women work, go to school or hang with friends and family.

    • THANKYOU!!!! I have found this to be true. Over time, the synch happens but it also drifts away again! I lived with three other women growing up, and now just my daughter, but I would say over time this is very true.

    • There is approximately 25% chance one woman will be experiencing a part of her period, while another woman, she lives/works with, is experiencing her’s. Increase the number of women, say living in a dorm to 8 and that % climbs up dramatically. Given our in borne desire for commonality, what some call normal, and our selective memory I can certainly see a number of women claiming to be in synch with women they live with or work with. Let me give you an example of a study I was involved with. 50 married women answered questions about their husbands moods, if their spouses had experienced episodes of depression, crying spells, not having hope etc.
      When answering singly 19% of the women believed their husbands had experienced enough of the 10 symptoms of clinical depression to be diagnosed as depressed.
      Part 2- another 50 married women were broken into 5 study groups and asked to fill out the exact same questionnaire, free to ask each other questions or share experiences. In part 2, 74% of the women claimed their husbands had experienced enough of the 10 symptoms to be diagnosed as depressed. Small study, interesting results. It was repeated yet again with the same results.
      We want to be seen as normal to those around us even if we must be selective of our facts to do so. We do this unconsciously.

  • Sooooooooo many times in my life have proven this to be true!!! My sister/ mom and i “same cycle”. best friends/friends and I that spent alot of time together “same cycle” . When i start a new job , either i start early or late (and im like clock work normally… text book clock work) or another will change to mine (like my recent co-worker, that i ride with to work )… ITS TRUE. We know it is..

  • All though this article is very interesting, and I have not fact checked it yet, I can say more research needs to be in play. Me personally, my cycle sync’s up mainly because I am not regular. When I hang around my friend who knows the exact time and day her “friend” will come, mine follows within two days or sometimes later that night. I live with 2 other women now, one is older and is not regular and sporadic due to menopause. The other started syncing a few months after moving in and hadn’t had hers in 2 years after previously giving birth. We all sync with in a few days and my body has never ben so regular. So myth or fact (I feel it as being fact) I believe what I know and I know more research needs to happen to truly understand this phenomenon.

  • Britany P Suthe

    This article is really silly. I couldn’t read it all because I got angry when it said that this phenomenon is a myth. This happens all the time to every owman and ai kno we it andim realll aygnry i cant ieven type pd my middle niane is peookey for perio d

  • Paternalistic condescension, my favourite kind. Do you think maybe women could figure out and factor in if their cycles were different lengths when they claim synchronicity? Or maybe the math is too hard for us, we should just go back to knitting kittens and baking cakes.

  • The author has one major flaw in his reasoning. That each woman’s menstrual cycle is the same length each time. His example where Subject A has a 28 day cycle and Subject B has a 30 day cycle fails as soon as you realize that those cycle lengths are averages.

    While anecdotes are not data, when a huge number of them come into play, it can be an indication that the conflicting data had been collected with some erroneous assumptions.

  • I have found that it depends on the women I’m living with. I almost never get my period and sometimes there’s no effect when I live with other women. But I have a special needs daughter who was often gone for months as a teen and I wouldn’t menstruate. When she was home, though, after a couple of months, I started my period within a week of her getting hers and soon we would be synchronized in that I’d start mine a couple of days after she did but every couple of months instead of a few times a year randomly.

    I’ve had a couple long term foster daughters yell at me because when I menstruate, everyone else does too, even if it’s in the middle of their cycles. I’ve had other women tell me similar stories.

    They can say it’s anecdotal but when so many women have this experience, the scientists are ignoring the fact that other factors could be involved such as how well the people know each other, how similar their pheromones are, whether they’re related, how close in age, in a relationship (whether with each other or someone else not living there, male or female), etc. Heck, maybe weather, climate, or location (the further north, the more inconsistent the days from season to season), diet, whether there is a male living in the house and ages of those men, and how many women are living together.

    We don’t know how many factors are involved. But I’m not one to believe hype at all, nor be swayed by friends’ claims of oddities (like ghosts or crop circles or conspiracy theories), and I believe in the scientific method, but I know there is something true about this phenomenon no matter what the scientists say.

  • Oh this is absolutely 100% true. I have lived enough of my younger years with enough other young women in college dorms, apartments, etc. to know this is true. I think it will also happen with women who work closely together in the same office settings over time. While you’re not “living together”, you spend enough time around each other on a daily basis that the hormones definitely pick up on these things. Why this happens or nature does this to women I have no idea. Obviously it has something to do with hormones and pheromones. But as to how this would benefit “mankind” in the reproduction of the species is a real mystery. THAT is the curious part, the why this happens. All I know is that personally I’m glad this part of my life is over.

  • “The egg is released from the ovary and travels down the fallopian tubes and in to the uterus. If the egg is fertilized and attaches to the uterine wall, pregnancy begins. ”

    Not quite. It’s a common misconception the fertilization occurs inside the uterus. The egg does not travel down the uterine tube right away. In fact, pregnancy begins in the uterine tube. That’s how ectopic pregnancies occur- the fertilized egg attaches before moving down into the uterus.

    As far as synching up goes, I don’t put much stock in it. People’s cycles have different lengths, which makes it a little difficult for them to match (for example, my mom has the typical 28 day cycle, whereas mine is in the 30s). I know anecdotal evidence doesn’t mean much, but I’ve never synched up with any of the girls I’ve lived with.

    • everything in the science world is myth if they have not discovered it yet , the fact is they do not talk to women and ask them , do you think the first female orgasm happened when science discovered its existence in the 20th century ? or that women had not found their clitoris before science .
      women are spiritually privileged we have a natural connection to the earth because like the earth we birth life , we are in our cycle one way or another 365 days a year , women realised that in order for our baby to survive when the men were away hunting we needed other women . women will only sync with women that we trust and have a sisterhood with , a bit like the male bromance thing .

      a lab study will not show this bond , this is why some families that are not close will not see any sync .
      women began to realise this and so started to do rituals , chanting and group gatherings in small groups together , women then used the cycles of the moon to share time together and made these a time of religious celebration to bring the group closer . these times of close relationships among women helped them sync their cycles closer therefore allowing them to control when babies were born so they could share the responsibility of care even breast feeding each others babies .
      no matter how big the group women will only be close to 2 or 3 of the women .
      all the stone circles of ancient times are about the cycles of the moon and fertility and only women knew about their own bodies ( nothing changes there then )

  • I am not an OB/GYN nor have I played one on TV, I practice in a branch of surgery. But I have three daughters and a wife, and I can honesty say the idea of synchro-menses is bunk. From what I was taught and experienced during a 6 week clinical experience along with my at home practical experience, I catch hell any and everyday of the month, for being a man. Somehow the entire unpleasant parts of MENstration has to be blamed on guys. If we could synchronize the outfit, life would be more pleasant.
    “in 1998, McClintock published another paper in “Nature” which found that if a woman was exposed to cotton pads soaked in the sweat of women in their follicular and luteal phases.”
    I would swear my brother Tom went out with one of the testing subjects, her friends called her “Stinky”.

  • I know that most people want to think thats its a myth. But i think that its only coz scientists’ experiments haven’t proved it doesn’t mean its not true. Take it from me, who’s shifted boarding schools and hostels a couple of times. Like for the previous two years, my periods had been consistently coming on the 26th aligning with my 3 roommates and then i moved early this year. And this month, they synced with my current best friend’s. How can they be consistent for two years and then just coincidentally change. I’m telling you, aint no myth there.

  • Hi just wanted to leave a comment about my personal experience with syncing cycles. My girlfriend and (yes we’re lesbian) have been living together for 3 months now before we meet my cycle was the beginning of the month lasting for 3 days her the middle of the moth lasting 5 days this 3rd month my cycle and her cycle started and ended on the same day.. So I believe the syncing is fact.. Ee spend every waking moment together work together chill all day together then go to bed together.. But just wanted to share my personal experience on the matter

  • I’ve experienced this on more than one occasion. Science poo poos it cos it can’t prove it either way ( bit like God’s existence). Some things just ARE, accept it 😉

  • I just have to comment on this because of my personal medical history. I was diagnosed with PCOS last year and had a hysterectomy based on my menstrual history alone. However, when my doctor removed my ovaries, he stated that they appeared to be two of the most healthy looking ovaries he has ever seen. Reflecting back on my history, I grew up with a mother that had had a hysterectomy at a very young age, and was not offered HRT. I did not have my first menstrual cycle until after I moved out and had a female roommate who had regular menstrual cycles. At that time my cycles synced with hers. I got pregnant, and moved into my own house, and did not have another menstrual cycle for 7 years, until I moved back in with another female with regular cycles. I immediately got pregnant again, and 6 weeks after delivering that child I had another pregnancy. I moved into my own house again, and was a stay at home mom for 5 years. I did not have a menstrual cycle for 4 of those years. At that time my oldest daughter started having cycles, albeit irregular ones, and I started having irregular cycles as well. I then started a job with another woman who was so regular she could almost tell you to the hour of when she was going to start. Low and behold, my cycles finally started being regular again! She left her position, and my cycles immediately stopped! I actually took several pregnancy tests to make sure that I wasn’t pregnant! After a couple of years I hired another woman who was in the process of menopause. My cycles came back, albeit irregular. When she stopped having cycles is when my symptoms that led my doctor to believe I had PCOS began. I realize that I am the exception, not the rule, but in hindsight i can honestly say with 99% certainty that my cycles not only synced with those around me, they were dependant on those around me!

  • Guys, just back off.
    The facts are not relevant–this is the most powerful female magick and it is not yours to touch or talk about.

  • “Either way, if I haven’t said it already, I’m glad I was born a man! You ladies get the short end of the stick when it comes to periods at least. ” you weren’t born a man, you were born an ass. What a stupid thing to say.

  • The author is horribly wrong and it is NOT a myth. Woman will link up. Our true history is being hidden. Women educate yourself. Scott, a man knows NOTHING about a menstrusl cycle. Travel the world over, study with indigenous people and you will learn we are all meant to have our cycle together. All of us. Most women will either bleed with the new or full moon an we are supposed to.

  • Did the experiment control for birth control pills and morning after pills? IMO any research into this phenomena is pretty worthless if the participants are ingesting artificial hormones.

  • I’m sitting here right now on the verge of crying. Every time my adult daughters visit and they are near or on their periods my emotions get all out of wack! I haven’t had any periods for 5 years and still don’t. I used to get the sore breasts and cramps now just the emotional part of it. It’s totally a fact!

  • Tickled by the audacity

    Men telling women that syncing is not real. LOL.
    Like how can they be so confident in their ignorance?
    They’ve NEVER had a period.
    Then calling US sexist because we correct them about OUR experiences LOL WOW

    • Daven Hiskey

      Ya, who cares about all the actual real world data carefully compiled in a scientifically rigorous fashion (including by women researchers). Clearly those researchers have an agenda against women on this topic… for reasons I guess.

  • Wow. Did you just mansplain the female menstrual cycle? And Daven, is it? Unless I am reading an article written by one of the female researchers I don’t care who you say complied data. Actually – I guess no one lies in the internet so I’ll believe everything I read.
    Did you know that a woman has about 400 periods in her lifetime? Bottom line – go out and get your own vagina – not one of those new ones but an antique vagina, if you will, so you get the full experience. Walk around with that bitch for the next 30 years, report back with your findings and then – MAYBE- you can offer your opinion.

    • Daven Hiskey

      “Unless I am reading an article written by one of the female researchers…” That is astoundingly sexist. And also quite a bizarre thought process given the present context. Would a woman researcher then have no right to ever discuss what the average penis size is for males given some set of data points? This article isn’t about what it’s like to have a period, simply about looking at collected data on a subject and talking about the results.