This paper reflects the research and thoughts of a student at the time the paper was written for a course at Bryn Mawr College. Like other materials on Serendip, it is not intended to be "authoritative" but rather to help others further develop their own explorations. Web links were active as of the time the paper was posted but are not updated.

Contribute Thoughts | Search Serendip for Other Papers | Serendip Home Page

Biology 103
2003 Second Paper
On Serendip

You Can't Smell It But It's The Pain of Your Existence: Pheromones

Diana Medina


I sit at a bar and there is something about him that makes him different from the guy behind. I tell my friend, "Isn't he attractive?" and she says, "not in a million years!" However, I proceed to say that if I were gutsy enough I'd start a conversation with him as I find him greatly striking - despite my friend's disgust. My friend and I leave the bar and I can't help but wonder why the random attraction to equally random people. What is it abut other human beings that give us "that feeling" way before we even get a chance to know them personally? What is it that sets one person apart from the other when it comes to sexual attraction? Is it animal instinct, is it social predispositions, is it mental archetypes, or is just plain chemical? Is it all of the above? My focus of research will be on the "chemical" part, so if you're a romantic, get ready to kiss cupid goodbye. He's out of arrows and his bow is gone.

Research done on this subject has brought about the theory that sexual attraction could potentially derive from hormones called Pheromones. These are airborne, mostly odorless chemicals that alter sexual behavior, mark territory, and influence reproduction throughout the animal kingdom. But whether humans send and receive "sex chemicals" is a hot and bothered topic. Recent studies suggest that chemicals emanating from our pores do affect the behavior and biochemistry of others. Fragrance companies have caught "whiff" of this research, and the Internet abounds with products sporting names such as "Primal Instinct" or "Rogue Male" promising to make you an irresistible sex magnet(5) While many scientists believe that human pheromones exist, they disagree about whether they have identified any specific chemical compound that causes other humans to react to it in a specific way. In the popular understanding, pheromones cause an instinctual, almost automatic sexual response, which scientists call a "releaser" effect. That effect is well studied in animals, but has never been observed in humans. Nevertheless, fragrance companies are focusing -- and funding -- research concerning pheromones' potential for sexual arousal. (1) We know that animals have signaling chemicals that induce sexual behaviors. For example, a male pig secretes the pheromone androstenone in his saliva, and when the female "smells" it, she goes into a mating stance. If humans do produce pheromones, the underarm is where we might do so, with its many glands and its proximity to a companion's nose. Our sebaceous glands secrete a clear liquid that becomes mixed with thousands of odorless compounds oozing from other glands. Bacteria on our skin break down those compounds into volatile molecules, both odoriferous and odorless, producing an "odor print" as unique as our fingerprints. Any pheromones among them would drift into our companion's nasal passage and stimulate specialized but still elusive receptors. Finding those receptors will resolve the dispute about whether humans have a "vomeronasal organ" (the exact mechanism for human pheromones, if they do indeed exist, is not known. The human VNO is underdeveloped and arguably vestigial.) - devoted to sensing pheromones, as many other animals do, or whether pheromone receptors are interspersed with olfactory receptors in the nasal passage.(4)

George Preti, an organic chemist at the Monell Chemical Senses Center in Philadelphia, first began researching this topic in the 1980s in collaboration with Winnefred Cutler of the University of Pennsylvania's psychology department. They hoped to explain the observation that women living together fall into menstrual synchrony, a finding made in 1971 by Martha McClintock, a leading pheromone researcher at the University of Chicago. Preti and Cutler discovered that women exposed to just the underarm extracts of other women adjusted their menstrual cycles to be in synch, and that male underarm extracts made women with irregular cycles more regular. They hypothesized that those underarm extracts must contain pheromones, because the effects could not be explained in any other way, and they were consistent with the way pheromones function in other mammals. (1)Recently, it has been reported that male underarm extracts can affect the cycles of a specific reproductive hormone in women. Those extracts also affected the mood of women, making them calmer and more relaxed. On the other hand, a 2001 study conducted with males by researchers at the University of Texas, described the smell of a woman's T-shirt as more "sexy" or "pleasant" during the fertile stage of her menstrual cycle than the shirt of the same woman during her infertile stage. (3) The reasoning behind both these tests is that two compounds with mixed reputation as pheromones - androstadienone, (AND) and estratetraenol (EST) and copulins - were at play. AND is a derivative of testosterone, EST is a poorly understood relative of estrogen and copuline is a strictly female substance, which is found in human vaginal secretions. (has been shown to both elevate male testosterone levels - directly linked to increased sex drive - and positively affect perceptions of female attractiveness in targeted males ) Could AND and EST be human pheromones? Some scientists are ready to say yes, because these chemicals considerately changed brain patterns as detected by EEGs, functional MRIs, and PET scans, and induce mood changes. (2) However, it needs to be noted, and not overlooked that those results were obtained from solutions of pure compounds with a thousand times the concentration found in humans.

These studies, however, did not examine physiological or biochemical changes and critics contend that the data did not support those conclusions. They point to inconsistencies with the numbers and to the small sample sizes and short time period of the studies. But the biggest problem is that the experiment can't be replicated because the chemical composition of what was being tested is unknown. Nonetheless, pheromone research is reshaping the fragrance industry, indicating that the romance of scent is not just the fragrance you put on your skin, but also the chemicals that are coming out of your pores. Still, there are so many factors affecting human communication that if pheromones do play a part, it isn't the main part.

So, I did end up developing the courage to approach this non-descriptive male at the bar and I proceeded to have the most obtuse conversation possible. The physical attraction remained, but anything else flew out the window of the bar as quickly as I realized my friend's phrase, "not in a million years," was exactly right. There was absolutely nothing interesting about him, nothing that fit my intellectual needs, nothing that suited my ideas of a good partner, of a possible good dad, or even less a possible "show and tell" prospect for my Thanksgiving dinner. So what happened? Well, the pheromones apparently played a role in awakening my sexual desire towards another member of my species, but it certainly did not do the trick of actually following it up. Therefore, when need be, put the blame for your failed relationships where it truly belongs or if you still remain a romantic blame cupid for his deplorable aim.


1), M. Delude, Cathryn Looking for love potion number nine: Scientists and perfumers are searching for the chemical scent that drives humans wild, The Boston Globe, Published by The Globe Newspaper Company, September 2, 2003

2), Kaufman, Kasey Pheromones at First Sniff, WBZ4 News Report, 2003.

3), Lee, Scarlett Pheromones: The Olfactory Love Letter, Varsity Science and Technology, Varsity Publications, 2000.

4), Pines, May, A Secret Sense in the Human Nose: Pheromones and Mammals, Seeing, Hearing and Smelling The World, A Report From the Howard Hughes Medical Institute.

5) Pheromone fragrances

| Biology 103 | Course Forum Area | Biology | Serendip Home |

Send us your comments at Serendip

© by Serendip 1994- - Last Modified: Wednesday, 02-May-2018 10:53:20 CDT