Do pheromones play a role in our romantic lives?


Related Articles

Sex Panther cologne, a fictional-but-now-actual product from the movie “Anchorman,” had Brian Fantana fooled with its claim: “Sixty percent of the time, it works every time.” And today this scene doesn’t seem too far from reality. Fragrance companies for years have been exploiting the concept of human pheromones that attract the opposite gender, and people are buying them despite the lack of conclusive science to back up the claim.

Pheromones are chemicals released by one animal that cause a physiological reaction when detected by another animal of the same species. The first pheromone was discovered in 1956 when researchers realized that even a tiny amount of the chemical bombykol, secreted by a female silkworm moth, would attract male moths even from great distances.

While that probably sounds like a handy trick you wouldn’t mind bottled up in perfume form — poor Channing Tatem and David Beckham would have to go into hiding on faraway islands — sexual desire gets a whole lot more complicated when it comes to mammals, particularly humans.

Think about it. Most of us have a physical type that we prefer, or at least certain physical traits that we tend to look for in a mate. You might be attracted to a certain type of voice, style or talent in another person — e.g., there’s a reason so many men choose to pick up a guitar. Our emotions, memories and experiences are all intertwined with our physical reaction to someone else. Scent is only one factor — but are pheromones involved in that one factor, and if so, how much?


Potential human pheromones

Humans can be a stinky species at times. If you have ever been in a New York City subway car with a man who hasn’t showered in weeks, you’re well aware of this. We have glands in our underarms, nipples and genital areas that produce odors, and some consider the odor-producing chemicals we secrete in those areas to be human pheromones. The main three: androsteonone, androstenol and androstandienone. Now say that three times fast.

Even if you’re convinced that we secrete pheromones, however, you have to prove two other things to truly make them pheromones: that other humans can detect them, and that they elicit a physiological response of some sort in those other people.


Human pheromone detection

Until fairly recently, it was believed that pheromones were only detectable through a part of the body called the vomeronasal organ, or VNO.

This theory is problematic when trying to prove that pheromones exist in humans because the VNO duct, which first shows up when we’re still in the womb, shrinks to a miniscule size by time we’re born and is generally considered to be nonfunctional in humans.

However, recent research has shown that the VNO isn’t necessary at all for pheromone detection. According to Scientific American, in one study, sows assumed a mating stance when they smelled a pheromone in boars’ saliva, even though their VNOs were plugged.


Pheromones and the menstrual cycle

One of the earliest studies attributed to human pheromones is Martha McClintock’s 1971 study indicating that women who live together, menstruate together — meaning, women’s cycles tend to synchronize over time if they’re around each other enough.

A 2007 study contradicted this, however, finding no evidence that women’s menstrual cycles were altered after living in dorms together for a full year. The researchers also critiqued McClintock’s work, saying its results were purely coincidental.

Another study suggested that male B.O. could modify women’s menstrual cycles. The researchers investigated the effects of placing armpit sweat on women’s upper lips — we hope they were paid well for this study — and found that it altered the length of their cycle. Additionally, it made them feel more relaxed, though we recommend trying other stress-coping techniques before you succumb to sniffing your boyfriend’s dirty T-shirts.

Finally, a 1986 study also found that women’s menstrual cycles became more regular after they were exposed to yet more armpit odor from men’s dirty T-shirts.


How pheromones make us feel

Various studies have analyzed how our perception of different body odors changes when other variables are thrown into the mix. Men, for example, rated the smell of women’s armpit and vaginal secretions — no, there was no prettier way to phrase that — as more pleasant when secreted during the pre-ovulatory or ovulatory phase of their menstrual cycle. This suggests men may be able to unconsciously detect through these smells when women are the most fertile.

McClintock — the live-together-menstruate-together lady — published another study in February 2002 in which 49 unmarried women sniffed boxes containing men’s dirty T-shirts and chose which box they thought smelled the most pleasant. The results would have made Freud proud: Women preferred the smelly T-shirt of men who were genetically similar — but not too similar enough to risk an incestual attraction — to their fathers.

Alleged pheromones actually reduced men’s sexual arousal and testosterone level in another study. Researchers had women watch a sad movie scene, took samples of their tears and had men sniff these unidentified samples. Though it did not elicit empathy like you may have expected, the men were actually “turned off” by the exposure to the samples, which makes you wonder if the smell of the tears signaled to them that sex was off the table at the moment for these ladies.


The case against pheromones

Despite all this research, many scientists contest the existence of human pheromones. A Slate article pointed out a 2007 study by Andreas Keller — a geneticist at Rockefeller University — that discovered that people reacted to androstenedione, a purported human pheromone, differently depending on their genetics. Some thought it smelled pleasantly floral; others considered it repulsive; and yet others couldn’t detect it at all. “A true human pheromone would have universal appeal across the species,” Slate pointed out.

Richard Doty, the director of the University of Pennsylvania’s Smell and Taste Center, wrote an entire book, called “The Great Pheromone Myth,” repudiating the existence of human pheromones. “We looked at the literature relative to the set of criteria that would distinguish a pheromone from a chemical,” Doty says on the University of Pennsylvania’s website. “In reality, almost everything you could show [illustrates] that almost all the situations of changed behavior were learned. Animals are very good at learning the meaning of chemicals.”

Additionally, he argues that one chemical excreted or secreted by a mammal could never be powerful enough to elicit a behavioral change in another mammal of the same species. “It’s an oversimplification of how chemicals work in the environment and how animals are affected by them,” Doty says. “People have oversimplified the nature of the olfactory system. It’s the brain that interprets what meaning is. Conditioning plays a very significant role in all aspects of human and mammal behavior.”


Should you get some pheromone perfume now?

Do as you please, but we’re going to keep relying on good ole’ fashioned personality — and maybe a sexy outfit — to do the trick. While there’s a good deal of research out there trying to pinpoint that elusive sex pheromone in humans, the jury’s still out on whether it exists and how powerful it could be.

George Preti of the Monell Chemical Senses Center in Philadelphia told the Smithsonian that while “researchers (as well as fragrance companies) have been hoping to find a human sex pheromone for decades, … so far the search has failed.”

“That doesn’t mean a human sex pheromone doesn’t exist,” Preti said. “It just means we haven’t found one yet.”

Even if it does exist, its effects would have to overpower all of those other factors that determine who we’re attracted to for it to work the kind of magic people are fantasizing it does — meaning, we doubt Axe commercials will ever actually reflect reality. If your body type and personality aren’t really Ryan Reynolds’ style, a spray containing pheromone-packed armpit sweat probably isn’t going to change his mind.