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An ode to the many evolved virtues of human semen

The views expressed are those of the author and are not necessarily those of Scientific American.

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Dear readers: I have come upon a secret treasure, a heretofore-unknown bounty of facts only recently unearthed by a team of evolutionary psychologists. A vital forewarning, though: although the data and information I am about to share oozes with the promise of dramatically improving virtually every aspect of your wellbeing, it can also be abused with tragic—even fatal—consequences. This is so much the case, in fact, that I debated the merits of popularizing this material and do so here only with great circumspection and caution. So please be wise in digesting this semen-related knowledge, and be wiser still in applying it to your own sex lives.

As with the origins of so many great scientific discoveries, this story begins with a serendipitous chain of events. “Our interest in the psychological properties of semen arose as a by-product of an initial interest in menstrual synchrony,” explain co-discoverers Gordon Gallup and Rebecca Burch, evolutionary psychologists from the State University of New York system, in a 2006 chapter about human semen. In particular, Gallup and Burch had stumbled onto a set of intriguing data from the mid-1990s showing that, unlike heterosexually active women residing together, sexually involved lesbians failed to exhibit the well-known “McClintock effect,” in which menstrual cycles in cohabitating women (as well those of females from many other species) are synchronized.  Since subtle olfactory cues (called pheromones) are known to mediate menstrual synchrony, write the authors, “This struck us as peculiar…”

… because lesbians would be expected to be in closer, more intimate contact with one another on a daily basis than other females who live together. What is it about heterosexual females that promotes menstrual synchrony, or conversely what is it about lesbians that prevents menstrual synchrony? It occurred to us that one feature that distinguishes heterosexual women from lesbians is the presence or absence of semen in the female reproductive tract. Lesbians have semen-free sex.


Perhaps you already see where this is leading. Gallup and Burch reasoned that certain chemicals in human semen, through vaginal absorption, affect female biology in such a way that women who have condomless sex literally start to smell different from those women who do not—or at least, their bodies emit the pheromones that “entrain” menstrual cycles among cohabitating women. (Their hunch was indeed borne out by reviewing the existing literature on menstrual synchrony.) But this happenstance discovery of asynchronous lesbians was just the tip of the semen iceberg for Gallup and Burch, who quickly discovered that, although much was known among biologists about basic semen chemistry, virtually nothing was known about precisely how these chemicals might influence female biology, behavior and psychology.

And that is a rather odd omission in the biological literature indeed, since there could hardly be anything more obvious in Darwinian terms than the fact that semen is, almost by definition, naturally designed to get into the chemically-absorptive vagina. Bear in mind that although they are often conflated in everyday parlance, along with many other less scientific terms, “semen” is not the same thing as “sperm.” In fact, you may be surprised to learn that only about 1 to 5 percent of the average human ejaculate consists of sperm cells. The rest of the ejaculate, once drained of these famously flagellating gametes, is referred to as “seminal plasma.” So in discussing the chemical composition of semen, it is the plasma itself, not the spermatozoa, that is at issue.

Now, medical professionals have known for a very long time that the vagina is an ideal route for drug delivery. The reason for this is that the vagina is surrounded by an impressive vascular network. Arteries, blood vessels, and lymphatic vessels abound, and—unlike some other routes of drug administration—chemicals that are absorbed through the vaginal walls have an almost direct line to the body’s peripheral circulation system. So it makes infinite sense, argue Gallup and Burch, that like any artificially-derived chemical substance inserted into the vagina via medical pessary, semen might also have certain chemical properties that tweak female biology.

It turns out that this insight, so obvious as to be all but invisible, has been a theoretical gold mine for this hawkeyed pair of adaptation-minded thinkers. But before we jump into their rich vat of seminal theory, let’s have a quick look at some of the key ingredients of human semen. In fact, semen has a very complicated chemical profile, containing over 50 different compounds (including hormones, neurotransmitters, endorphins and immunosupressants) each with a special function and occurring in different concentrations within the seminal plasma. Perhaps the most striking of these compounds is the bundle of mood-enhancing chemicals in semen. There is good in this goo. Such anxiolytic chemicals include, but are by no means limited to, cortisol (known to increase affection), estrone (which elevates mood), prolactin (a natural antidepressant), oxytocin (also elevates mood), thyrotropin-releasing hormone (another antidepressant), melatonin (a sleep-inducing agent) and even serotonin (perhaps the most well-known antidepressant neurotransmitter).

Given these ingredients—and this is just a small sample of the mind-altering “drugs” found in human semen—Gallup and Burch, along with psychologist Steven Platek, now at the University of Liverpool, hypothesized that women having unprotected sex should be less depressed than suitable control participants. To investigate whether semen has antidepressant effects, the authors rounded up 293 college females from the SUNY-Albany campus, who agreed to fill out an anonymous, written questionnaire about various aspects of their sexual behavior. Recent sexual activity without condoms was used as an indirect measure of seminal plasma circulating in the woman’s body. Each participant also completed the Beck Depression Inventory, a commonly used clinical measure of depressive symptoms.

The most significant findings from this 2002 study, published with criminally modest fanfare in the Archives of Sexual Behavior , were these: even after adjusting for frequency of sexual intercourse, women who engaged in sex and “never” used condoms showed significantly fewer depressive symptoms than did those who “usually” or “always” used condoms. Importantly, these chronically condomless, sexually active women also evidenced fewer depressive symptoms than did those who abstained from sex altogether. By contrast, sexually active women, even really promiscuous ones, who used condoms were just as depressed as those practicing total abstinence. In other words, it’s not just that women who are having sex are simply happier, but instead happiness appears to be a function of the ambient seminal fluid pulsing through one’s veins.

And it gets better. A smaller percentage (4.5 percent) of the sexually active women who “never” used condoms were less likely to have attempted suicide than were those who “sometimes” (7.4 percent) and “usually” (28.9 percent) and “always” (13.2 percent) used condoms.

Relax, settle down, take a deep breath—I know what you’re thinking. This is a correlational study and there are scores of possible confounds, both those that the authors anticipated and controlled for in this study design (by all means read the actual article for more details—but please do note that these between-group differences in depression panned out even after controlling for the use of oral contraceptives, days since last sex, frequency of sex and duration of the relationship with the male partner) and probably some that you can come up with on your own. Even the authors urge some degree of scepticism:

It is important to acknowledge that these data are preliminary and correlational in nature, and as such are only suggestive. More definitive evidence for antidepressant effects of semen would require more direct manipulation of the presence of semen in the reproductive tract and, ideally, the measurement of seminal components in the recipient’s blood.


Now I’m hedging here, because there are all sorts of equally fascinating directions I can go from this point. But one thing I do want to mention, with a helpful nod from the authors of this study, is that the antidepressant effects of seminal plasma may not be limited to vaginal absorption of its mood-brightening chemical properties. “It would be interesting to investigate,” write Gallup and his coauthors, “the possible antidepressant effects of oral ingestion of semen, or semen applied through anal intercourse (or both) among both heterosexual couples as well as homosexual  males.”

So in my plumbing of the empirical literature for studies on unprotected anal sex among gay males, otherwise known as “barebacking,” I came across a load of research on this very topic. Most of this work is couched, understandably so, in the HIV-prevention literature. One particularly telling study, though, comes from a 2005 report from the journal Nursing Inquiry , in which Canadian investigators Dave Holmes and Dan Warner interviewed barebacking gay males—not while they were engaged in the act, but through later introspection—about their motivations for preferring unprotected anal sex over condoms in light of the obvious dangers of infection. The most intriguing result to emerge from this study, in the context of Gallup and Burch’s overall theoretical perspective regarding the psychobiology of semen, was that so many of the barebacking interview subjects viewed the exchange of semen through unprotected anal sex as providing them with a palpable sense of “connectedness” with their same-sex partners, one that happened only with the internally, unimpeded ejaculation.

Unfortunately, rather than investigate the possible psychobiological effects of semen exchange in this dynamic, Holmes and Warner leer through a fairly typical postmodernist lens to explore the symbolic nature of semen exchange in barebackers. Now, I ask you, which is the more informative paradigm for understanding why gay men would practice unsafe sex through unprotected anal intercourse: an evolutionary biological account taking into consideration the chemical composition of seminal plasma and its possible affects on attachment among gay men, or a symbolic, postmodernist perspective like the following one advanced by Holmes and Warner (in all fairness, this is just a snippet, but a good taste of their approach):

The body becomes the locus of never-ending fights, a carnal battlefield. The escape route (lines of flight) is intrinsic to the deterritorialization of the Body-without-Organs through which one becomes someone else. However, the lines of flight could have paradoxical effects. Indeed, they can be avenues of creative potential or, conversely, paths of great danger. Yet, it is ‘always in a line of flight that we create’ … ‘that we must continue to experiment with such lines.’ Lines of flight (nuclei of resistance of resingularization and heterogenesis) permit freedom to surge through a process of creative transformation and metamorphosis.


Trust me, even in context that paragraph reads like the authors were cobbling together a braille sentence using the random distribution of acne on someone’s back. Sorry to sound a bit testy, but while such soupy postmodernist rhetoric may still have its place in certain scholarly circles, in dealing with something as clinically important as unprotected sex among vulnerable populations, a scientific understanding of these people’s motivations is essential before any intervention of their high-risk behaviors can even begin to occur.

You may also be beginning to realize the dangers that I alluded to at the start of this essay. For both men and women, heterosexual and homosexual, knowing that the penis is capable of dispensing a sort of natural Prozac—whether obtained vaginally, anally or orally—without also considering the viral arms race involving sexually transmitted infections, can lead to very tragic decisions indeed and many undocumented high-risk private bedroom “experiments.” But here’s just one reason to put the brakes on such plans: The HIV-virus, which evolved long after these adaptive antidepressant factors, has apparently come to pirate human semen, such that certain protein factors in seminal plasma, particularly a protein called prostatic acid phosphatase , make HIV up to 100,000 folds more potent than it is outside of the plasma.*

In any event, Gallup and Burch’s model reminded me also of those oft-cited Papau New Guinea tribes, such as the “Sambia,” and their semen-ingestion rituals involving young boys. On the surface, there’s a puzzling scenario here: such cultures have long histories of being embroiled in violent warfare and thus they tend to place extraordinarily high value on expressed masculinity. Yet ritualized homoerotic practices involving young boys fellating older males in order to ingest their semen are common. In a 2000 issue of the Archives of Sexual Behavior , Gilbert Herdt, a cultural anthropologist who studied the Sambia, along with his colleague Martha McClintock (the same McClintock named for the menstrual cycle synchrony effect discussed earlier), describe how “… by the age of 11–12 (Sambia) boys have become aggressive fellators who actively pursue semen to masculinize their bodies.”

In the past, this semen ritual has been conceptualized by cultural anthropologists such as Herdt mostly in symbolic terms. Yet, just a hunch, but since testosterone from the seminal plasma could penetrate the oral mucosa, along with a surfeit of other hormones and chemicals having possible spin-off effects on male behavior, it is not inconceivable to me that there may be genuine psychobiological consequences of semen intake occurring in these young swallowing males that are not wholly out of line with the Sambia’s own folk beliefs. It might not be a theory you want to run by your local pastor or should bring up at your next PTA meeting, but you get the idea.

But let’s get back to non-hebephilic semen ingestion. In addition to their semen-as-antidepressant model, Gallup and Burch have worked out many other intricate, persuasive arguments about how the various chemicals in human semen served—and continue to serve—biologically adaptive functions for both sexes. For example, among the more curious ingredients in human semen are follicle-stimulating-hormone (FSH) and luteinizing hormone (LH). The reason this is curious, point out Gallup and Burch, is because these are distinctively female hormones. “What are female hormones doing in human semen?” The authors speculate, and convincingly so, that the presence of FSH and LH in human semen is related to concealed ovulation in human females.

Unlike females of other primate species, women do not have breeding patterns governed by season or standardized cycles, and there are no obvious signals—such as a fire-engine red, swollen rear end—giving away their time of the month. So for a naïve human male, impregnating a woman as a consequence of sexual intercourse is much more a roll of the dice than it is for males of other species in their mating behaviors. Just as with any other species, though, getting the timing right so that release of semen coincides with the release of eggs is key. As a counterdefense against women’s concealed ovulation, male evolution had a trick up its sleeve, which was the ability to manipulate the timing of a woman’s ovulation to suit his own insemination schedule—that is to say, semen chemistry seems to give premature eggs a nice little nudging. Hence the conspicuous presence of FSH (which causes an egg in the ovary to ripen and mature) and LH (which triggers ovulation and release of that egg).

In support of this theoretical claim about semen chemistry and concealed ovulation in human females, consider that chimpanzee semen lacks the FSH hormone altogether and the presence of LH is rather negligible, which makes sense, of course, since chimpanzees are cyclical breeders and ovulating females display blinking Vegas-style marquees by way of swollen, multicolored anogenital regions. “Thus it would appear,” reason Gallup and Burch:

…that the chemistry of human semen has been selected to mimic the hormonal conditions that control ovulation, and as such may account for instances of induced ovulation (ovulation triggered by copulation at points in the menstrual cycle when ovulation would otherwise be unlikely).


I’ve barely scratched the surface of the evolved semen literature. Here’s a snapshot of other recent findings from Gallup’s lab: semen-exposed women perform better on concentration and cognitive tasks; women’s bodies can detect “foreign” semen that differs from their recurrent sexual partner’s signature semen, an evolved system that, Gallup believes, often leads to unsuccessful pregnancies because it signals a disinvested male partner who is not as likely to provide for the offspring; women who had unprotected sex with their ex-partners—and therefore were getting regularly inseminated—experience more significant depression on breaking up than those who were not as regularly exposed to their ex’s semen (and they also go on the “rebound” faster in seeking new sexual partners, which presumably would help fix their semen-deprived depression). And the list goes on.

Before I bid adieu, please accept, in all sincerity, my humblest apologies for what is likely to be a flood of bad, off-color jokes—men saying, “I’m not a medical doctor, but my testicles are licensed pharmaceutical suppliers” and so on—tracing its origins back to this innocent little article. Ladies, forgive me for what I have done.


Want more Bering in Mind? Follow Jesse on Twitter @JesseBering, visit, or friend Jesse on  Facebook.

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*Editors’ Note, 9/28/10: The word "brakes" in this paragraph was originally mistyped as "breaks." Thanks to the readers who pointed out the error.



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  1. 1. Ben82 3:32 am 09/23/2010

    *very* interesting! :)

    though… obviously I have to go to the literature here myself, but:

    the most obvious and difficult factor to control for would be the *motivation to use condoms*. this might well correlate with depression or mood and thus be a confounding factor. (wo)men having protected sex might be more risk-aware, less trusting (or naive) and so on…

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  2. 2. swiftfoxe 12:51 pm 09/23/2010

    I hypothesize that there may exist an effect of vaginal mucus on male psychobiology as well. It would be evolutionarily advantageous. I am interested to see any results of experiments and/or data analysis on the other half of the population involved.

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  3. 3. ectopist 4:19 am 09/24/2010

    This is so fascinating! Swiftfoxe’s conjecture appeals to me too. But one thing you don’t discuss is what is actually the point of menstrual synchrony. There seems to be a soft assumption that it enhances female interpersonal empathy ("sistahood"), but it seems much more likely that it has a more direct adaptive function, such as preventing the monopolization of reproduction by one or a few dominant males, thereby maintaining genetic variety, and optimizing the likelihood of conception in a context where men of reproductive age spend long periods away from the group in search of food. Any thoughts on that? In any case, we need some serious research dollars to be invested in testing the possible benefits of oral, anal and epidermal absorption (even if it seems unlikely that they are as effective a route of delivery as the vagina – though I take the point that for those people unlucky enough not to have a vagina, they may be the sole remaining alternatives). For such a wideranging research agenda, my efforts alone will not suffice.

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  4. 4. Minerva 11:47 am 09/24/2010

    This article refers to LH and FSH as being "distinctively female hormones", which is inaccurate and misleading at best. LH is necessary for the production of testosterone, and FSH is necessary for maturation of germ cells (which gives rise to gametes, i.e. sperm). Is it possible that LH and FSH are present in semen as a biproduct of their use in testosterone and sperm production, and the effects, if any, of LH and FSH on females is an exaptation?

    Further, it is not as simple as a blast of LH and FSH to induce ovulation. There is a particular rhythmn and pattern to it (the order in which these, and *other* important hormones, are increased or decreased, and the timing of it all in a concerted effort). Hiccups in this process can cause various reproductive issues, including infertility. None of that is mentioned in this article, which simplifies the process in a grossly misleading way.

    I enjoyed the article up until that point, but found that entire portion to be frustrating. I am reserving any opinion on the rest of the subject the article covered until I can read the actual peer-reviewed studies, in which I hope such constraints are more thoroughly addressed.

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  5. 5. sterculius 12:03 pm 09/24/2010

    Although I’m unqualified to evaluate or even comment on the technical validity of the tentative conclusions of the study, from the personal perspective of an otherwise straight male who enthusiastically enjoys performing fellatio and ingesting ejaculate, I can wholeheartedly agree with the opinion suggesting the mood enhancing qualities of semen. It’s the quintessential "happy meal"

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  6. 6. guynoir 1:50 pm 09/24/2010

    I have read that seminal plasma is known to change female behavior in that women form tighter bonds with someone whom they are regularly getting, uh, supplied.

    Very interesting article, avoiding some of the long, hard mathematical explanations that tend to make me sleepy and getting right to the creamy social research and easy to swallow chemistry.

    I came.

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  7. 7. MJ.Drew 3:48 pm 09/25/2010

    Question: If it becomes established that women who receive the package are happier, does it then become unethical to conduct a study where you randomize some of those women into a "start using condoms for the duration of this study" group.

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  8. 8. AutismNewsBeat 9:45 pm 09/25/2010

    One more example of the vas deferens between men and women.

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  9. 9. shroud 10:12 pm 09/25/2010

    Here’s a breakdown of the hormones in semen that may affect mood and sex drive:

    Also, from the same site, a post "What are female hormones doing in semen?"

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  10. 10. Tyrtaeus 10:59 am 09/26/2010

    I can now tell wife the more sex we have,the more blissful life she’ll have. Any chance of placebo effect in this plasma?

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  11. 11. aj1984 2:35 pm 09/26/2010

    Fascinating article. I do have a qualm with the basic premise, though: that women’s menstrual cycles synchronize only if semen is present in the vagina. My menstrual cycle started synching with my friends’ cycles by early high school, long before I was sexually active. Further, I have lived in many different places and my cycle always adapts quickly to room mates’ cycles, despite the fact that I have only had condom-less sex where semen would enter my body once in my life. I know I am far from alone on this.

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  12. 12. JoJo&JoJo 6:18 pm 09/28/2010

    I find the menstrual syncronicity fascinating. Is this nature’s way of stopping the male from swapping partners when one woman isn’t sexually active? The natural urge may be to move to the next available woman in the group, but if she is also menstruating…?

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  13. 13. royniles 11:28 pm 09/28/2010

    I hear the Sambia are searching for a way to pasteurize and bottle any excess for export as an organically extracted medicinal decoction.

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  14. 14. Daniel35 1:09 am 09/29/2010

    So does it matter if they swallow? Can these drugs survive stomach acid?

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  15. 15. royniles 2:11 am 09/29/2010

    Good question. The Sambia have also market tested soft suppositories and were bending over backwards to make this a successful venture.

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  16. 16. pradhangeorge 3:45 am 09/29/2010

    = May we have more sensible research like this one to show what we knew but didnt perceive hitherto why we enjoy hetero copulation, the semen into the vagina/throat/>blood>brain and the vaginal jooses thru the mans buccal-throat/>blood>brain.These articles wld make for adhering to perma partners, w/o the fear of virus/germs and the interfering nonsense latex.===mbbs/1950/ind./ECFMG 1973.

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  17. 17. AScientist 9:45 pm 09/29/2010

    Excellent, but factually known for decades, at least. Anal or oral delivery also produces an effect, but it is less pronounced in the subject than in response to intravaginal deposition of semen.

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  18. 18. Ric Locke 10:14 pm 09/29/2010

    #4 Minerva: Are FSH and LH required for those functions in monkeys? If so, the lack of those hormones in monkey sperm tends to confirm the hypothesis.

    Fascinating. What leapt to my mind was variances in drug reactions — I myself require up to 10X the "normal" dosage of most statins for a clinically effective dose. Equally, there are people who are hypersensitive. Might different levels of sensitivity to the effects of the "drugs" in sperm be part of the explanation for different levels of, e.g., promiscuity?


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  19. 19. brianc 10:38 pm 09/29/2010

    I have a question for the "hawkeyed pair of adaptation-minded thinkers": if semen accounts for the synchrony of menstrual cycles, the McClintock effect, then why do virgins living together also experience this effect?

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  20. 20. AScientist 11:21 pm 09/29/2010


    "virgins" hahaha, yes. very funny.

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  21. 21. Koblog 11:29 pm 09/29/2010

    Using evolution, please explain how semen and sperm came about.

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  22. 22. brianc 11:58 pm 09/29/2010

    Whatever. I think their theory holds little merit. Female menstrual synchrony has been observed in many cultures, across many generations: premature sexual activity wasn’t always as common as it is now, nor in other cultures.
    Ascientist (I take it your ‘a-’ prefix means you are not one, as in the word "asexual" or "amoral" or "asynchronous") surely you don’t mean to suggest that all females are sexually active in all cultures, in all generations?

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  23. 23. Bill R 2:58 pm 09/30/2010
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  24. 24. Bill R 3:01 pm 09/30/2010

    I took particular note of the following fascinating sentence, "But this happenstance discovery of asynchronous lesbians was just the tip of the semen iceberg for Gallup and Burch"

    Now we know why the Titanic went down.

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  25. 25. Eric_Jycek 7:56 am 10/1/2010

    Too bad the cost of STDs outweigh the benefits of semen.

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  26. 26. uri 1:20 pm 10/1/2010

    A straight-forward double-blind study is begging to be performed, confirming any effect semen might have on women. The study population is sexually-active, heterosexual women whose intercourse practice *excludes* contact with semen by any means whatsoever (they always employ condoms during intercourse, etc.)

    This population is divided into three groups: (1) Semen is applied to the vaginal wall by an applicator; (2) A placebo is applied to the vaginal wall by an applicator; (3) nothing is applied to the vaginal wall.

    The Semen will be tested and confirmed to be healthy (it contains no negative virus or bacteria such as HIV-AIDS, other STD, etc.) The semen will be "randomize" by the following procedure: Semen from several (at least 10) healthy donors will be combine into a single mixture. For further study (budget permitting) Group 1 may be divided to receiving semen with or without sperm.

    The application frequency for groups #1 and #2 should be determined for each woman by the frequency of her intercourse frequency, at least once or twice per week is preferred only in order to reach conclusive results faster.

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  27. 27. masterofmeander 8:07 pm 10/1/2010

    I certainly enjoyed this article, writing and content…but the dismissal of the Holmes and Warner “snippet” simply dismayed me.

    For the record, I found their prose purple shot through with turquoise in a commanding argyle pattern–more “tart” than “tartan”– made vivid by a steamy infusion of apricot scents lurking behind a cognitive veil gone to mildew a long time ago. In one sentence–there!–I catch the mutterings of early, early Proust; in the next, echoes of an a cappella-and-piccolo melody as haunting– and historically relevant, surely–as a rap song performed by that post-nihilist, prenuptial cadre of Viennese Boy’s Choir veterans “gone south” as they say). Something…Baptist stirred between clauses, upright and pious, resentful, defiant, rather badly stained. I sensed the stagger-and-bleat of a Lancet editor even as some Chem wept in the bowels of chem lab at–Carnegie Mellon?–as Hume hummed through ideological transitions, still with the lisp. If there had been a paragraph break, just one, I know I’d have seen Plato running Socrates’ projector, or the other way around, throwing shadows of birds and doggies on the wall, each with enormous genitalia, unless those are beaks, all accessorized with epaulets resembling chapped knuckles with fringe. Stunned to silence by adjectives pretending to art, adrift in Darkness-also-Oneness-with-Other, I heard the jack-boot heels of “Scientific Method” stutter in a hallway, lay sudden rubber, then tap the drum solo from “Innagoddadavita” (the long version), however it’s spelled.

    I tasted vanilla in the finish, and paprika, though that might have been lunch. Not once did I feel anything so “bumpy” as Braille.

    Frankly, I can’t believe I’m the only one who felt this way. I mean, if that was the case…?

    This semen stuff? In capsules or gel caps? At Cost-co…when?

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  28. 28. random1234 11:00 am 10/3/2010

    Jesse mentioned the possible relationship of the semen-testosterone-mascilinity link, but if this link stands true (which seems feasible), then the effects of testosterone on females must be mentioned.

    Testosterone is found in both genders, but significantly more in males. One of the obvious, tested, effects is that it boosts the libido and feelings of sexual intimacy in females. Such a deliver of testosterone in seminal fluid would, in turn, increase the likelihood of more sex acts (which, from an evolutionary stand point, would increase the likelihood of reproduction.)

    Another slightly off-topic fact worth mentioning is that the act of kissing transfers testosterone from the male to the female. And you can see where that would lead!


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  29. 29. bello 7:37 pm 10/6/2010

    My question is–do men’s vices –smoking, recreational drugs, prescription drugs, crummy food– come through the semen and effect the recipient?

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  30. 30. ahtuheutpuho 2:17 pm 10/11/2010

    This is so fascinating! Swiftfoxe’s conjecture appeals to me too. But one thing you don’t discuss is what is actually the point of menstrual synchrony. There seems to be a soft assumption that it enhances female interpersonal empathy ("sistahood"), but it seems much more likely that it has a more direct adaptive function, such as preventing the monopolization of reproduction by one or a few dominant males, thereby maintaining genetic variety, and optimizing the likelihood of conception in a context where men of reproductive age spend long periods away from the group in search of food. I have read that seminal plasma is known to change female behavior in that women form tighter bonds with someone whom they are regularly getting, uh, supplied.

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  31. 31. ahtuheutpuho 2:18 pm 10/11/2010


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  32. 32. volcanovaporizers 4:45 am 11/4/2010

    really a great review…
    [url=] VolcanoVaporizers[/url]

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  33. 33. ClaudiaP 7:59 pm 12/21/2010

    Is there some BENEFIT to menstrual harmony that lesbians or anyone might be missing out on? Just wondering.

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  34. 34. Jaeger 10:55 am 12/29/2010

    This is interesting and all, but how much of the theorized anti-depressive attributes of semen have to do with the fact that women who are most likely to have regular unprotected sex are also most likely to be in committed long-term relationships?

    And does that have a greater influence on their well-being than regular contact with semen?

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  35. 35. two-eyes 8:34 pm 12/29/2010

    A confounding observation from personal experience: Just spending time with an attractive man can make my period come early. It doesn’t matter whether we ever take our clothes off. My theory has been that pheromones trigger my menstrual cycle to speed up.

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  36. 36. two-eyes 1:58 am 12/30/2010

    Jaeger, you make an excellent point. Lack of attention to the relationship variable (in both this article and the original abstract) seems scientifically negligent (not to mention ethically problematic). Unfortunately, such reductionist approaches have far too frequently corrupted scientific findings and reporting in the past.

    For most of the 20th century, for example, researchers who reported legitimate evidence of neurogenesis immediately lost professional credibility as well as the possibility of advancement. Why did men who reported real facts (now unquestionably validated) become professional pariahs simply for speaking the objective truth?


    1) Neuroscientists had passed down the unsupported prejudice that we don’t generate new brain cells, ever.

    2) Researchers silenced their questions because they’d seen others professionally ruined for daring to supply contrary evidence or ask the "wrong" questions.

    3) The chief of neuroscience at Yale insisted on overly reductionist methods. (He eliminated learning and relationships as variables that could have physical *effects on the brain. Therefore, he arrogantly neglected to control crucial variables.) When other researchers used more advanced methods than those used at Yale at the time, the other researchers were deemed inferior because they weren’t at Yale. Ugh! Do these people live their lives observing nothing, not even obvious mediating variables, in the world around them?

    I hope we can soon update scientific standards for acceptable research practices. Too often professional blindness to human relationship variables leads to inaccurate results. We know that learning and relationships have observable effects on brain structures and biochemistry. It’s time that researchers design research with current knowledge in mind. It’s also time that reporters stop unquestioningly passing on schlocky research findings for the sake of sensational headlines.

    BTW, I’m wondering why Bering included the tangential, competitive-sounding comparison between semen analysis and "a symbolic, postmodernist perspective." It seemed a distraction from all of the main points of the article, and certainly criticizing someone else’s approach does nothing to strengthen the validity of the explanation addressed in this article. (If anything, it just creates suspicion of weakness in the main argument.) What was up with that? It seemed kind of like a defense of imaginary turf or something.

    *Note: "effects" is the correct spelling for the noun. (It is misspelled in the article.)

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  37. 37. drosen23 2:42 pm 03/5/2011

    The same thing that happened to Minerva, happened to me. I like Bering’s articles, but when he characterized FSH and LH as "female" hormones, and wrote that they might induce ovulation, I turned off!

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  38. 38. AntonTherapy 7:22 pm 04/18/2011

    I found your article while researching the benefits of semen (searching for Gallup/Birch).
    Recently Dr. Lazar Greenfield resigned as the Surgery News Editor after backlash from his brief notations in a 2/11 article of semens benefits, even alluding that it was a better gift for Valentines Day than ‘chocolates’. Albeit the articles peculiar Valentine summary, the scientific support of the healthy chemical properties of semen remain. Thank you for your enlightening article.

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  39. 39. a31pthink 2:29 am 06/23/2011

    Probably the most entertaining scientific article I’ve ever read. Jesse Bering, you’re like a Dan Savage for science nerds.

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  40. 40. Gjorgov AN 6:15 am 07/28/2011

    The researchers limited their `discovery’ of the semen-as-antidepressant story to psychological effects (`defects’) only. However, the better observable and quantifiable biological aspects of semen and its physiological impact on women are not mentioned.

    The evidence of a hypothesis-testing study showed that the elimination or absence of some ingredients in the seminal fluid, elimination achieved mainly by condomization (and withdrawals), induces at a significant levels fatal outcomes to many a women, among which is the breast cancer is the most remarkable epidemical disease. It is not mentioned, but would be of interest to know as to why the biological aspects of condomization, and the resultant multitude of multitude of specific sex- (gender-) diseases in women and girls, have been neglected for more than 30 years. The historical truth is confirmed once again that the effective suppression (censorship) of a scientific study/evidence is done at the sole account of grave consequences to its own population. Namely, the condomization of female sexuality has been defined long ago as the root cause of the ever-rising and excess breast cancer epidemic in middle-aged women in the country and worldwide, as well as the rampant anorexia-bulimia (conveniently called “eating”) disorders in schoolgirls, college women (daughters), brides, and other young and other women. Furthermore, a potential of primary (non-chemical, not-for-profit) prevention of the current, unabated breast cancer epidemic could be
    The results about the condom to breast cancer risk is presented and further elaborated in the following selected editions:
    Reproductive Health of Women: An Attempt to Define Breast Cancer Prevention. Macedonian Journal of Medical Sciences, 2010;Jun. 15, 3(2): 169-179. Web:
    Breast cancer risk assessment to barrier contraception exposure. New Approach. Contributions Soc Biol Med Sci MASA, 2009;XXX, 1, 217-233. (Macedonian Academy of Sciences and Arts), Web:
    Anorexia and Bulimia Nervosa in Young Female Patients and Barrier Contraception Practice. Asklepios, International Annual of History and Philosophy of Medicine (Sofia) 2009; Vol. III (Vol. XXII, Old series): pp. 97-108,
    Breast Cancer: Rationale for an Etiologic Hypothesis. A Reappraisal of the Clinical, Experimental, and Theoretical Aspects of Neoplastic Processes, Pseudopregnancy Complex, and the Possible Role of the Seminal Prostaglandins. University of Pennsylvania School of Medicine and Hospital, Philadelphia, PA, 1980, and Matica Mak. Publ., Skopje, 1996. (Submitted to the Library of the U.S. Congress, 1996)
    I will appreciate if you could convey my communication to your readers.
    Arne N. Gjorgov, M.D., Ph.D. (UNC-SPH, Chapel Hill, NC)
    Author of “Barrier Contraception and Breast Cancer,” 1980: x+164

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  41. 41. hsextant 6:08 pm 01/9/2012

    Like swiftfoxe’s comment (#2) above I suspect that this indeed may be a two way street. This suspicion is based on my extensive research on a data sample of one couple (my wife and I) and a huge government grant (consisting of a tax exemption for one rug rat that unfortunately expired prior to the completion of our research).

    Before I proceed any further, I find I must provide the standard warning, my commentary is limited to monogamous couples maintaining absolute fidelity in their sexual behavior. If you do not fall in the category, do not read the following comments. BTW absolute fidelity means that…absolutely no fiddling around with strange stuff…ever!

    Anyhow back in the days long, long ago when my wife and I had to deal with the f-word, you know, fertility, we would have long periods where we were forced to use condoms as a birth control method. Both of us found the method to be completely unsatisfactory, not for the stated method of birth control, but for the unstated reason of why we were having sex. Actually I believe that condoms when properly used by sober people with a good understanding of fluid mechanics will find that condoms will approach 100% efficiency in birth control. Why fluid mechanics? Well sex is a fluid based sport. So one has to understand the nature of fluids to successfully avoid unwanted pregnancies. For instance, condoms will do absolute nothing for carelessness in oral sex. She on he, a nice long appreciative kiss, then he on she and bingo–its all up to fluid mechanics and stochasticity. So unless you want to bundle up before you do anything, yuck for both she and he, the use of condoms requires a lot of smarts, sobriety, and some degree of an ability to maintain an erection. But used intelligently condoms are an effect birth control method. However to me, for a couple trying to express love and intimacy to one another for the purpose of maintaining a human pair bond, condoms may actually be destructive. They should be used only as a last resort by a loving monogamous couple.

    Did I mention that this is all my opinion and not to be construed as fact? Due to a lack of a research budget, sufficient sample size, and a cushy tenured position in some university, not to mention the academic credentials to engage in such research, I like a theoretical physicist have had to rely on pondering. Unlike a theoretical physicist, I am not very smart or well educated in this field of endeavor. As such this remains pure speculation by a layman…is there a pun there?

    So back in our fertile days, my wife and I were at certain periods forced to use condoms for birth control. We both hated them but neither of us could figure out why. Think about it, they are not that bad. Yes, you have to be careful, but really what is so bad about condoms?

    Sensitivity–yeah, you suffer a loss of sensitivity, but really? Is it that bad? No. It still feels pretty damned good.

    Interruption–you have to stop and put the condom on. Actually we found this to be a positive aspect of condoms. I provided the materials, foam, lubricant, unpackaged condom and she did the installation. It was actually very intimate and possibly the only thing that we liked about condoms. We actually enjoyed the installation process–it was fun.

    Rapid exit–yep, you have to leave before things go soft…the sooner the better. I would say that this was our biggest objection to condoms. We both wanted me to stick around a bit. You can’t. Out you go, hurry off! That sucked, but again was it that bad? Well, no, but it still sucked.

    So whats left? Why hate the use of condoms so much? Its not that bad. Well there was this vague feeling that we hadn’t done anything. We went through the motions, and it was fun, but…there was this odd empty feeling. We both experienced it. We were in love, had a good marriage, no problems, but wow, sex is kind of empty. Why? Oh it is probably just psychological. There is a sheet of rubber between us. It seems less intimate.

    This was a long time before the Gallup / Burch study, or even having the Internet available. So I pondered this. My research was aided by serendipitous discovery on my part. One day I was fooling around on her down there digitally (not in the sense of opposite of analogue) and discovered that she was quite dry. As an experiment, I took a dab of Cowper’s fluid and carefully applied it to the interior wall of her vagina. (See Wikipedia for a definition including a photo which will remove all doubt in your mind as to what Cowper’s fluid is and where it comes from. Damn! Why couldn’t we have had Wikipedia when I was a youth?) In a few seconds she became extremely moist. Amazing! Incidentally I have tried this experiment since my first discovery and it always works, but again note that my sample size is relatively small (just my wife and I).

    So now I had two pieces of theoretical evidence, condoms suck, and Cowper’s fluid seems to have a rather dramatic affect on vaginal lubrication. Then with my acute powers of observation, I wondered why does a penis have a glans? Pretty odd contraption on what seemed to me could basically be a featureless stick with a hole in the end. Why this elaborate construction with extremely thin tissue on the glans? I wouldn’t call the covering on the glans skin, it seems more to be a membrane to the untrained eye. So what is with the glans?

    Another interesting facet was that the vagina is very efficient at absorption. My wife had some “lady trouble” and her gynecologist gave her a prescription for a medication that was absorbed vaginally. Fascinating! But why would a vagina be efficient at absorption?

    So I pondered and contemplated and came up with a theory. You have heard of the old adage about taking a shower with a rain coat on? I would submit that the use of a condom is worse. It is like making love with a sheet of rubber wrapped around your penis. More to the point, I think it is like having a phone conversation on a dead phone line.

    What is the purpose of sex besides reproduction? Well I think it is a deep level, ancient form of communication. What is being communicated? A lot of biochemistry using fluids as a transport medium. I believe that just like semen, vaginal fluids are a literal brew of love potion number 9. I think that the vaginal is actively exuding and absorbing good stuff and so is the penis, through the glans. Block the fluid interchange, and you block the communication. Worse is that the couple has just put their bodies through the rigors and joy of coitus. All systems are go. Hump de hump, hump, hump, hump. Houston we have orgasm. Houston? Houston? I don’t read you Houston? Then nothing. Wow it was just like masturbating, fun but very lonely.

    So like like swiftfoxe, I would love to see some research on this. I have searched but other than Tantric notion of semen retentions, I have found nothing on male absorption of post coital bio-chemistry. Personally I feel the use of condoms is damaging to a couple because there is this expectation of a big rush of biochemistry that is supposed to shout “I love you” to the primordial swamp beings in our psyches and it doesn’t happen. So the intellectual part of your brain is quite satisfied that you had sex, not very good sex, but sex, meanwhile down in the swamp they are saying “Sex? What sex? We haven’t had sex in a long time.” If true, and Gallup / Burch study would indicate that it is at least half way true, then I think loving MONOGAMOUS couples should think hard about the use of condoms.

    Oh incidentally I did find out that the glans acts like both a shock absorber and what I would call a hydraulic accumulator. The soft puffy end of the otherwise hard penis prevents impact trauma to the cervix and vagina during energetic thrusting. But it also acts like a hydraulic relief reservoir against dangerous spikes in blood pressure within the penis. OK, I can buy that, but if you look at the surface tissue of the glans, it looks like a thin membrane designed for absorption and possibly exudation.

    Oh, one other conclusion I can make from my theoretical studies, the male habit of putt, putt, putt, then rolling over and going to sleep is really shortsighted. Lads, a bit of advice from an old man, do your thing, make sure she does her thing, and then while things are still up and lively get into the scissors position–it is very comfortable for both of you. Reinstall all the plumbing parts. And have a good cuddle, some pillow talk, tell her that you love her, and then both of you drift off to sleep all put together. While you are doing that, your glans is sucking up on all that wonderful love potion # 9 that she has exuded for the purpose of saying “I love you with all my heart.” Stick around guys, there good stuff down there!

    This life time I am stuck. No money, no power, only questions–damn few answers. Next life time I intend to be the charismatic CEO of a giant software company. My wife and I will form a research trust foundation for the study of long term, committed, monogamous relationships and the biochemistry of coitus. We will fund huge studies of what’s going on in the big sex organ on top of our shoulders and find the true function of Cowper’s fluid.

    Again the warning, I don’t want to hear any crap about promoting unsafe sex. The only way to have safer sex than monogamous sex is to have sex with yourself. So again this commentary is limited to monogamous couples maintaining absolute fidelity.

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  42. 42. dgrendahl 3:32 pm 04/4/2013

    One of the things I hope this article or blog might address for men is what do they experience by the loss of their semen if anything. I as one male experience in the days following a case of depression and just feeling out of sorts for almost a week before coming out of it. I have found that I’m not the only one. It is now called, “POIS.” Can anyone address this issue for men?

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  43. 43. hsextant 1:56 am 04/14/2013


    You may have an allergy to your own semen:

    Or you may be having a post orgasmic hangover:

    Personally, I have reservations regarding Marnia Robinson and her research. She seems a little too much on a mission. So I offer up “The Passion Cycle” not as a recommendation but as simply a source of information that you may or may not find relevant. Be cautious. I have not read her new book, Cupid’s Poison Arrow. I did read her previous book Peace Between the Sheets and I was uncomfortable with her level of fervor for pushing her beliefs.

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  44. 44. MelvinW 11:34 am 10/5/2014

    The moment you start your foundation through evolution’s mindset, you are doomed. You are like child that will never grow up and just keep asking the question, Why? Why is the sky blue? Why is the ice cream sweet? Why is sweet , sweet? And so on. You are going to go in circles. Who came first, the chicken or the egg?

    There might be some truth to this article, but just some. I want the truth, the whole truth. Half truths is a lie.

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  45. 45. Willg 1:44 am 04/4/2015

    The Feminists are going to have a fit on this one – Especially Hanna Rosin with her “End of Men” bullcrap. Think of all the garbage we have been fed – that women have unprotected sex because thats what the man wanted. Every guy i spoke to agrees that its the woman that usually wanted them to “come inside” of them.

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