Pheromone excerpts from The Science of Sex
While that pheromone may have been a dud, there are pheromones which play some role in sexual attraction. A subclass of pheromones called copulins has been identified in vaginal secretions just before ovulation, which are thought to play a role in stimulating the sexual interest of males. Since women are most apt to become pregnant around ovulation, it is not surprising that nature has contrived a means to facilitate intercourse at that time.
Interestingly, copulin production is reduced by the Pill and by antibiotics (1). Women who are on the Pill or antibiotics, or women who are at a phase in their menstrual cycle in which copulin production is low, might benefit from using synthetic copulins to enhance their sexual appeal. Women who are ovulating would not be appreciably helped by spritzing on some copulins, since they have about as much need for additional copulins as Eskimos have a need for iceboxes. However, Paul Spinrad, author of The RE/Search Guide to Bodily Fluids, said that only one-third of women produce copulins. If that is true, then the two-thirds of women who do not produce copulins might especially benefit from using synthetic copulins. Incidentally, copulins don’t necessarily have to be applied to women to be effective; synthetic copulins could be applied to a man who wished to boost his libido.
Some research suggests that the mechanism by which copulins achieve their effect is by increasing testosterone production in men (2). The proximity of the nose (site of the pheromone receptors) to the vagina may explain why many men find cunnilingus to be so stimulating, since this maximizes pheromone reception. Some European women dab their vaginal juices on areas in which perfume is traditionally applied, such as on the neck and behind the ears. This rationale for this is obvious: by juxtaposing copulins to the man’s nose, a greater dose is delivered.
One author speculated that the supposed male preference for blondes and redheads is attributable to their higher production of copulins. Though entertaining, there is no scientific support for this theory. Research does suggest that the heightened attraction evoked by copulins is more apt to benefit women who are less attractive than women who are very attractive. Presumably, men are so revved up by just looking at gorgeous women that adjunctive attractants such as copulins elicit relatively little additional appeal. Since copulins do more to enhance the appeal of women who aren’t stunning, in effect they decrease the importance of optical attractiveness and hence help level the playing field in the competition for men.
Failure to respond to copulins or other pheromones may result from a variety of causes such as nasal infections or allergies, smoking, certain genetic defects, head injuries in which the olfactory nerves are sheared, and possibly incipient Alzheimer’s disease.
My introduction to copulins came years before I heard that term. One of the nurses with whom I worked made a birthday cake for me. I ate a piece of it after getting off work, then made the long drive (2½ hours) home with the remainder of the cake sitting on the passenger’s seat. During my trip I became ravenous — not for food, but for sex. This shocked me because my libido had been disappointingly low for years, and now I was burning with passion and far hornier than I’d ever been as a teenager. What also surprised me was that when I later masturbated my sexual sensation was markedly more intense than it had been for the past decade, and perhaps more than it had ever been. The occurrence of such a profound and unexpected sexual rejuvenation so soon after eating that cake made me wonder, “What on Earth was in that cake?”
I eagerly awaited seeing the nurse who made the cake so I could ask her. When I learned the ingredients, nothing rang a bell — nothing to explain the effect that cake had on my sex drive. The nurse smiled knowingly, as if she knew more than what she’d told me. I pressed her for more details, told her about the reaction that cake triggered, and begged for more information. She told me it was “just a cake” (yeah, right), and gave me that same smile. I repeatedly tried to pry the information out of her — every time, I received the same “it’s just a cake” answer and the smile that said otherwise. I’d eaten cake on hundreds of prior occasions, and that had not stimulated my libido or sensation the slightest bit. This cake was different. But how?
The next step was to make a list of the constituents of each ingredient. Again, nothing rang a bell until years later when I read about the chemical makeup of the various copulins. I immediately recalled one of those chemicals as being a constituent in one of the cake ingredients. Eureka! I’d finally made a connection to explain this heretofore unsolved mystery.
In reality, eating that cake probably did not do anything for me. What helped was the odor (or, more precisely, the vapor), since copulins are disseminated through the air. I did not realize it at the time, but having that cake so close to me in a small closed space (my car) for so long was a great way to magnify the copulin concentration in the air. Bigger dose, bigger response.
Copulins in History
In ancient times, Greeks and Egyptians thought that sleeping (just sleeping, not intercourse) with a young virgin could restore the libido of elderly men. This may seem like a strange custom to modern people, but there is some validity to it. Compared with elderly women (who were presumably married to the elderly men), young women are far more likely to produce copulins, assuming that they are sexually mature. Furthermore, for reasons given later in the book, virgins are somewhat more likely to produce copulins than other women. Thus, the quaint custom of sleeping with virgins may seem wacky, but it can be efficacious.
The key to this is not sleeping together, it is prolonged proximity. Sleeping in the same bed is one of the most practical ways to be close to someone for eight hours, but you could conceivably achieve the same effect by studying together, watching movies, or jointly reading this book.
Finally, don’t put much emphasis on either youth or virginity. While young virgins are more likely to produce copulins, the difference is slight until women are postmenopausal.
These chemicals, which stimulate the sexual interest of nearby males, are discussed in more detail elsewhere in this book. Besides increasing libido, copulins also augment sexual pleasure. In general, the hornier you are, the better sex feels. However, in some people (especially men with initially low testosterone levels) the libido boost is dwarfed by the increase in sexual sensation, leading me to conclude that copulins have a specific effect, not just an indirect effect in which increased libido leads to increased pleasure. This is illustrated by the following case history provided by a man who read an earlier edition of this book:
Judging by my sexual frequency of two to three orgasms per week, I think that my libido is about average. However, my sexual sensation is usually quite poor. If sex always felt that way for everyone, I am sure that people would not give a hoot about sex. Fortunately, in some circumstances my sexual sensation is even better than it was when I was in high school. After decades of dating hundreds of women, and sleeping with a few dozen of them, it was enlightening to read what you had to say about copulins, especially the part about how they can increase sexual sensitivity (not just libido), because this meshes with my experiences. I’ve noticed that if I spend time next to certain women, my sexual sensitivity goes from disappointing to wonderful. Ordinarily, when the sensitivity is poor, it takes a very pleasurable stimulus like a great vagina for me to obtain much sexual satisfaction. Masturbation at those times gives me very little pleasure. However, when my sensitivity is high, virtually anything can feel GREAT — even basic masturbation using my hand. This intensified sensation now only occurs after I spend time near certain women, and there is no correlation between my attraction to the woman and the response, if any, that I obtain in terms of heightened sexual sensitivity. Considering that I noticed this effect before I heard about copulins, and considering that some of my male friends have noticed a similar effect, I think it is real.
At the risk of sounding like a real jerk, I will now tell you how I utilize this effect. My current girlfriend is beautiful, sexy, intelligent, fun, and interesting. She is just about everything a man could hope for, except that her vagina is just average, and she evidently does not produce copulins. Intercourse with her gives me mediocre pleasure, except when my dates with her were preceded by extended proximity to a copulin-producing woman . . . then the pleasure is fantastic.
Copulin production can be decreased by an estrogen deficiency, taking the Pill or antibiotics, or douching. It is important to remember that copulins do nothing until they lock onto receptors in the nose of a nearby male. Consequently, dissemination of copulins is just as important as production. Thus, women should avoid trimming pubic hair, especially that which immediately surrounds the vaginal opening. Those hairs can wick away secretions and accelerate evaporation. To some extent, heavy and/or occlusive clothing can also hinder transmission of the copulins. And let’s not neglect one of the most important factors: physical proximity. The closer a man’s nose is to the vagina, the greater the copulin “dose” he will receive. If your husband claims he is too tired for sex, have him rest his head on your lap instead of a pillow; he just might change his mind!
Copulin Q & A:
Q: How does a woman know if she produces copulinsor if she needs supplemental copulins?
A: If cost is no object, you could have your vaginal secretions analyzed by a lab. For most people that is not a feasible option, so they must be more ingenious and determine the likelihood of their copulin production by analyzing clues and probabilities. That may sound difficult, but it is not.
Awoman is less likely to produce copulins if she:
· ■ Uses oral contraceptives.
· ■ Uses (or has recently used) antibiotics. If your doctor wishes to prescribe an antibiotic, ask him if it is truly needed. In some countries (most notably the United States) antibiotics are grossly overutilized, fueled by the desire of doctors to avoid litigation and to kowtow to patients who are often viewed as consumers in need of wooing. If an antibiotic is needed, tell your doctor that you would prefer one selected to kill the specific bacteria causing the infection, not a broad-spectrum antibiotic (3). In addition to minimizing the impact on the natural flora of bacteria in your vagina and gastrointestinal tract, this minimizes the risk of bacterial resistance (which is both a personal concern and a menace to society).
· ■ Douches (this reduces the number of beneficial bacteria in the vagina, similar to the effect of antibiotics). Incidentally, even vinegar or plain water douches deplete the vaginal flora. Many “feminine hygiene” products have a similar effect.
· ■ Bathes instead of showering.
· ■ Uses soap that contains the antibacterial agent triclosan (as many now do). This is more of a problem in women who bathe instead of showering, but it can affect the vaginal flora even with showering, depending on a number of factors: the concentration of triclosan in the soap, how much is used, how much gets into the vulvar folds and wicks its way into the vagina, how well the woman rinses, and the hardness of her water (4).
· ■ Swims or otherwise uses a pool or hot tub, especially ones that contain chlorinated water.
· ■ Uses tampons.
· ■ Uses Vaseline® (or other brand of petroleum jelly, a.k.a., petrolatum) as a sexual lubricant. This can affect copulin production by altering vaginal flora. Other sex lubes may do this, too, but petrolatum is not water soluble, and it tenaciously clings to the vaginal lining.
· ■ Is postmenopausal or is otherwise deficient in estrogen.
· ■ Her partner does not seem especially eager to have sex. Granted, there are many factors that influence intersexual attraction, but some of the chemistry between men and women is chemistry, and copulins are part of that chemistry. Incidentally, a man’s sexual interest is not always directly expressed. A man who holds a burning passion for you is not only more likely to be affectionate and outwardly lustful, he is also more likely to be attentive, more thoughtful and considerate, sweeter, and in general more willing to bend over backwards to please you. He is also less likely to be unfaithful.
· ■ Her partner does not obtain intense sexual pleasure from intercourse. This assumes that the man can respond to copulins, and that he has no major diseases or conditions that interfere with his sexual pleasure. Otherwise, if copulins are present, a woman could have poor vaginal sensate characteristics and the man should still be able to obtain very gratifying stimulation from contacting even a callused hand, thanks to his heightened libido and sexual sensitivity.
Here are a few more points to keep in mind:
· ■ Even if you do produce copulins, their production varies throughout the menstrual cycle. Research indicates that they peak just before ovulation, which is fine if your only goal is to get pregnant. If you wish to elicit more sexual interest from your partner at other times, or if you want to do everything possible so he is more apt to treat you like a queen, you may wish to supplement with synthetic copulins. Copulins are not a sexual or relationship panacea, but they can add that “something extra” which makes a relationship sparkle.
· ■ Paul Spinrad, author of The RE/Search Guide to Bodily Fluids, contends that only one-third of women produce copulins. This may seem implausible, but it meshes with my experience (and the experience of many other men) that some women possess an irresistible “something extra” that cannot be explained on the basis of their appearance, personality, or intellect. Furthermore, copulins are produced by bacteria, and women differ in the types and amounts of vaginal bacteria normally present. I’ll expand on this topic in the next section.
· ■ Some women eat yogurt (or instill it into their vaginas) to replenish the beneficial bacteria killed by douching or use of antibiotics. A typical yogurt containing live cultures usually includes three species of bacteria: Lactobacillus acidophilus, Lactobacillus bulgaricus, and Streptococcus thermophilus. For years, Lactobacillus acidophilus (LA) was thought to be the primary beneficial bacteria species in the vagina. Hence, the rationale for using yogurt is that since yogurt contains LA, use of it could restore the vaginal flora and hence “crowd out” harmful bacteria. However, microbiologists now know that there are over 60 species of lactobacilli, andmost of the lactobacilliin the vagina are Lactobacillus crispatis (LC), Lactobacillus jensenii (LJ),and less frequently Lactobacillus gasseri (LG), all of which are species with different metabolic characteristics than LA. Those bacteria feed off glycogen in the vagina and produce bacteriocins (5), hydrogen peroxide, and lactic acid that acidifies the vagina, lowering its pH (6) to around 3.8 to 4.4. This acidity is optimal for lactobacilli but inhibitory for most bacteria and other infectious agents, such as the HIV virus (7). Besides varying with pH, the type and amount of bacterial flora in the vagina varies with the woman’s age, race, geographic location in some cases, general health, clothing (8), sexual activity, hormone levels, phase of the menstrual cycle, choice of contraceptive (e.g., the spermicide nonoxynol-9 is toxic to lactobacilli), vaginal and cervical epithelium, vaginal fluid, cervical mucus, and even such esoteric factors such as the oxidation-reduction potential. Other possible variables are her diet (9), type of panty liner (if used) (10), and resident bacteriophage population (11). In short, the vagina is a complex ecosystem. Like most ecosystems, it can be knocked out of balance by adding something that is not normally present, such as antibiotics or yogurt. It is easy to understand how antibiotics wreak havoc: they kill the good bacteria that normally keep the bad bacteria in check. Once the good bacteria are decimated, the bad bacteria take over. So how can yogurt and its Lactobacillus acidophilus disrupt the vaginal flora? After all, isn’t yogurt practically a synonym for a healthy food? Yes, but that image is overly simplistic. To the degree that yogurt’s bacteria are able to populate the vagina (12), such colonization may be good in that it suppresses pathogenic (disease-causing) germs, but bad in that it also suppresses the normal lactobacilliin the vagina (such as LC and LJ). Why would LA suppress LC and LJ? Because organisms compete for limited resources — whether they are plants competing for sunlight and water, animals competing for food, or bacteria competing for what keeps them alive: in this case, the vaginal secretions. If you add LA, LC and LJ will be suppressed. In effect, they will starve, and their numbers will decrease. Because lactobacilli vary in their ability to produce defense factors and other chemicals, replacing the normal lactobacilli with LA alters the vaginal chemistry and impacts copulin production. In a study titled Antagonism among vaginal lactobacilli, researchers from the University of Illinoisconcluded that vaginal lactobacilli do indeed antagonize one another. In a separate study (Phylogenetic analysis of vaginal lactobacilli reveals novel species) conducted in collaboration with researchers from other universities, they concluded that the vaginal lactobacilli usually present are distinctly different from lactobacilli in food. Thus, expecting yogurt’s Lactobacillus acidophilus to pinch-hit for the normal vaginal lactobacilli makes about as much sense as expecting a young chimpanzee to substitute for a kindergarten student. While many different species of lactobacilli have been isolated from the vagina (13), most are genetically close to LC, LJ, and LG. Comparing the proportion of copulin-producing women to the frequency of isolating Lactobacillus acidophilus from the vagina suggests that LA is not the species responsible for copulin production. Bottom line? Yogurt is probably not going to help your love life, and may even hurt it by suppressing other lactobacilli.
The population of LC, LJ, and LG varies in different women, and there are genetic differences even amongst members of the same species — just like the fact that you are not genetically identical to your neighbors. Until scientists determine what species and strain is the best copulin producer, is there anything you can do to boost your copulin production? Yes, but this procedure is probably something most women would find objectionable. Hence, I’ll present this not as a recommendation, but merely as food for thought. The procedure is simple: transfer vaginal secretions from a copulin-producing woman (who is disease-free, of course) into the vagina of a non-producer. Essentially, this is just the process of inoculation. Humans transfer bacteria from one to another all the time, and implanting lactobacilli is just an intentional transfer with a specific goal in mind rather than the inadvertent transfer that characterizes bacterial emigration mediated by kissing, coughing, sneezing, shaking hands, and so forth.
If lactobacilli inoculation is too radical for you, consider the following. Since copulins are believed to achieve their effects by increasing testosterone production, you could dispense with the worry about whether or not copulins are present by a more direct route: giving supplemental testosterone. However, I am not convinced that the only mechanism by which copulins work is by boosting testosterone production. Furthermore, giving supplemental testosterone is often not practical. Let’s say that you’re a single woman competing with other women for the best possible mate. It is not feasible (or legal) to slip a man some testosterone at the start of every date to enhance his ardor and attraction to you, but applying supplemental copulins is a viable option that may achieve the same or greater effect.
As mentioned above, vaginal flora varies with sexual activity. Researchers found that beneficial flora could be lost by receiving oral sex or by intercourse in which semen is deposited in the vagina at least once per week. The fact that LC and LJ can be so easily eradicated by mere exposure to saliva or semen offers some insight into why women are so prone to lose their colonizations by LC and LJ. One study found that during an 8-month period 34% of women initially colonized by LC lost that colonization, and 50% of women initially colonized by LJ lost that colonization. The only good news is that 35% of women who were not colonized by beneficial bacteria acquired such a colonization during an 8-month period. However, once acquired, colonizations are frequently lost.
Given the link between copulin production and bacteria, and given the fact that beneficial vaginal flora are not very tenacious, it isn’t surprising that most women do not produce copulins. However, rather than saying that one-third of women produce copulins, I think it would be more accurate to say that one-third of women make copulins at any one time. For example, consider a group of 100 women with 33 copulin producers. Several months later, statistically 33 women will still produce copulins, but not all women in the original copulin-producing group will be in that group at a later date; some women will stop making copulins, while others will start.
Since copulin production is so variable, might this be one reason why the sexual appetite of men can change for no apparent reason? If you’re a woman wondering why your lover seems less interested in sex, it may not be because he loves you any less or because he’s having an affair — it may be something as simple as a change in your vaginal flora.
FootnotesCopulins are produced by bacteria normally present in the vagina. Antibiotics (especially the broad-spectrum ones that kill or suppress many bacterial species) decrease copulin production by inhibiting bacteria.
This would explain why copulins can improve sexual sensation, especially in men with initially low testosterone levels. Incidentally, this boost in sexual sensitivity can be marked in some people. I will discuss this topic in more detail in the next chapter.
In medical school, we were taught to identify the likely pathogen before instituting treatment. Definitive cultures take time to yield results, but microscopic examination of specimens (such as a sputum sample) can often give immediate information that helps the physician choose an antibiotic targeted to the type of bacteria identified on the smear. However, most physicians do not microscopically examine specimens before initiating antibiotic therapy. Instead, they often guess what the likely pathogen is, and then choose a broad-spectrum antibiotic that kills other possible culprits in case their guess is not correct.
Thorough rinsing may be impossible if you have hard water, as many soaps react with hard water to form soap scum. This is deposited not only on the surfaces of your shower or tub, but also on your skin. Liquid soaps are less likely to form soap scum, with a few exceptions. For example, I have noticed that liquid Ivory® rapidly reacts with my water to form a tenacious scum. The water in my home is not particularly hard, and I had the same problem with this soap when I used it in my last home, which had a water softener.
Bacteriocins are antibiotic-like substances produced by bacteria that kill or inhibit other bacteria, often closely related species. Interestingly, one of them (nisin) is commercially exploited as a food preservative, and researchers are investigating its use as a disinfectant in a variety of applications ranging from kitchen utensils to medical devices such as catheters and endotracheal tubes.
pH is a measure (on a scale of 0 to 14) of the acidity or alkalinity of a solution. A pH of 7 is neutral. The closer the pH is to zero, the more acidic the solution. The closer the pH is to 14, the more alkaline the solution.
Researchers discovered that the incidence of HIV is much greater in women with bacterial vaginosis, a common condition in which lactobacilli are replaced by anaerobic bacteria that alkalinize the vagina. The proliferation of these harmful bacteria produces a vaginal discharge (often mistakenly attributed to a yeast infection) and a characteristic fishy odor that may intensify after intercourse.
The effects of clothing vary with the type of fabric, its thickness, and configuration. For an example of the latter, Dr. Dean Edell reported that thong underwear can create a “tunnel” that increases transmission of bacteria from the anus to the vagina. Furthermore, some clothing has antimicrobial properties. For example, one company is now embedding ultra-fine silver fibers into textiles (silver has been used in various forms for centuries as an antimicrobial agent). I once assumed the antimicrobial effect would be confined to within the fabric, but the November 10, 2003 Forbes magazine contained a related article which reported that shoes were sanitized by wearing X-Static® socks, which contain silver-coated fibers. The X-Static web site mentions use in applications including sanitary products and underwear.
In an article in the May 31, 2003 issue of Science News, researcher Mark Schell from the University of Georgia confidently speculated that diet will be proven to affect the intestinal flora. Considering that your food is their food, this seems like a very safe bet. Since intestinal flora can affect vaginal flora, it is likely that diet — by affecting intestinal flora — indirectly affects vaginal flora, too. Moreover, diet potentially affects vaginal flora by other mechanisms (e.g., dietary indiscretions that lead to hyperglycemia in diabetics, predisposing them to vaginal yeast infections).
One study found that using conventional panty liners (as opposed to vapor-permeable “breathable” ones) affected the vulvar skin microclimate, increasing its humidity and pH.
A bacteriophage is a virus that infects and lyses certain bacteria. The world harbors a staggering number of bacteriophages. According to an article in the July 12, 2003 Science News, there may be 10 bacteriophages for every bacteria on Earth.
Many scientists think it can, while others are skeptical. Since Lactobacillus acidophilus is sometimes cultured from the vagina, I think it’s quite plausible that adding LA to the vagina can result in a successful colonization.
Such as Lactobacillus rogosae, L. johnsonii, L. gallinarum, L. fornicalis, L. casei, L. vaginalsi, L. fermentum, L. mucosae,and L. paracasei.