Friday Weird Science: Does Your Aunt Only Visit at the Dark of the Moon?

Nov 05 2010 Published by under Friday Weird Science, Uncategorized

Sci will admit that I often have a hard time with euphemisms. Particularly euphemisms about That Time of the Month. Your period. Your menstrual cycle. devil? Anyway, I never get the euphemisms. I don't know why, but when people say things like "my aunt came to visit while I was wearing white pants!", my response is usually "why would your aunt care about your pants...oh...OH...". Even when people say it's "that time of the month", I think "oh YEAH! I have to pay my bills too...oh wait...".

But there's one euphemism that seems really common, particularly among the fantasy books that Sci so loves (and devours like candy when given the chance. My current recommendation is this one. SO BRILLIANT). In the female-centric fantasy novels that Sci devoured as a young'un, they usually talk about the advent of your period. Often it's couched in these wrenching, difficult, spiritual awakening kinds of ways. But uniformly, no one calls it 'your period'. That is SO not fantasy enough. No, they call it 'moon days', or some variation on that theme.

Why moon days? Because it's a tradition old as dirt that women cycle with the phases of the moon. I think it's supposed to be partly spiritual, and partly something awful about women being more base and therefore under the moon's nefarious influences.

But then, you have cause to wonder. Traditionally (maybe not now with lots of women under hormonal contraceptives), women cycled together...but DO they cycle with the moon? Law. "THE REGULATION OF MENSTRUAL CYCLE AND ITS RELATIONSHIP TO THE MOON" Acta Obstet Gynecol Scand 65 :45 - 48, 1986

(Insert obligatory wolf howling at moon image here, I hear they bite more. :))

But first, let's go back to the menstrual cycle.

Above you can see the basic hormonal changes associated with the menstrual cycle. The menstruation goes right at the beginning, and ovulation comes up to 12 days later, near the halfway point of the cycle. This would mean that, if women have their periods at the DARK of the moon, they would ovulate at the full moon. Sadly, that correlation wasn't examined.

What was examined in this paper was a whole pile of crazee. It's like Friday Weird Science made of pie, moonbeans, and plenty of snark.

But it started out ok. First thing, they took 826 women of reproductive age, and asked them the date of their last menstrual period. The data came out like so:

You can see they broke down the number of periods over the past four months, and associated them with the lunar phase. They did indeed get 28% of the female population having their periods at the new moon, and another 12% having it immediately after.

But...but..., well, that's 40% associated with the new moon, so that's good. But that means 60% aren't. While they got significant differences between the new moon and other times of the month (and that looks good), there ARE other factors at work here. For example, do these women live in close proximity to each other? Most were from large cities.

So I'm actually prepared to buy the fact that women are cycling more often around the new moon. I will buy that. But I don't know WHY. And for all we know, it could having NOTHING to do with the moon. I think more evaluation is in order here.

But luckily for us (at least for weird science), they didn't go that route. Instead...they looked at melatonin...which doesn't make a lot of sense (especially since they only looked in three women), noting that melatonin peaked during menses and dropped during ovulation.

And then they went WAY off in left field. Their idea was to try and restore fertility in women by using "lunar therapy", which is apparently used to adjust the nephroposmonegaf, vitenergia, and blood (well, i know what ONE out of three of those are..., but the other two I couldn't even find on Google!) back to the lunar cycle they feel these women should be on, in an effort to restore menstruation and make them fertile.

To this end...they gave them a concoction.

From the new moon to the full moon, they gave them this:

(WTF is hepato-splen...)

And from the full moon to the next new moon, they gave them this:

I'll be honest, I have NO IDEA what most of that is. It's an herbal concoction of some sort. They note they gave no hormones. They found that they got an 85% effect, with 4 people resuming regular bleeding, 5 some bleeding, 8 a little bit, and 3 none, out of a total of 20.

Okaaay. Who can point out some problems with this study? Anyone? Anybody? I'll wait.

Ok, what did you come up with. Cause here's what I've got:

2) You call an 85% effect when only 4 women had regular bleeding and the rest little to none?!
3) You give no hormone, but do not note the chemical contents of ANY of that pile of herbs you've been feeding those women. Herbs aren't made of fairies and sunshine dust, they are made of chemicals, like everything else. They could very well have hormonal effects, in fact there are lots of plants that have hormonal effects. I ain't gonna believe in your "lunar therapy" until you show me what's in those herbs.


So, this paper, it fails to convince me. I'm prepared to see if their first experiment can be replicated...and if it can be, WHY?! What does it have to do with the moon? Or does it happen to coincide? But the rest...well...I mean, that's just all dogs barking at the moon for all I can tell.


Law, S. (1986). The Regulation of Menstrual Cycle and its Relationship to the Moon Acta Obstetricia et Gynecologica Scandinavica, 65 (1), 45-48 DOI: 10.3109/00016348609158228

7 responses so far

  • Samantha Vimes says:

    Whu do people do this and call it science? Well, call me cynical, I'm guessing they hope to sell their woo concoction.

  • Minnie says:

    What I want to know is: if 40% of women menstruate during the new moon, is there there some sort of correlation between PMSing and being a werewolf during full moon?


  • Ian says:

    Here is my speculation (moonshine?) on the menstruation – moon synchrony:
    Consider early scavenger-gatherer hominids sharing the savannah with really dangerous predators who can sniff out blood at great distances, e.g. lions. If the menstruations were asynchronous the hominids would always be having to avoid the predators' attentions. Synchronising would limit the danger time. Having the danger time coincide with the full moon might make night time defence easier.
    Or not, who knows? I've tried searching to see if any studies have been done on this but cannot get passed all the moon goddess woo.

  • Quirina Roode-Gutzmer says:

    The only correspondence between the cycles of the moon, which is 28 days long, is that the menstrual cycle of females of the species homo sapiens sapiens is on average 28 days long.

  • gv says:

    You see doctor, I have this pain in my nephroposmonegaf...

  • rehana says:

    Any idea what percentage of women actually have a 28-day cycle?

  • [...] “Although more women have been documented to menstruate around the full moon,” (though see this, by Scicurious) “research has generally failed to confirm any association between the full moon [...]

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