You've probably seen the sketchy online ads for pheromone-laced fragrances: "Cologne contains highest concentration of pure human pheromones available… get more looks, conversation, and attention from women."
The promise: A spritz of love juice will turn anyone around you into a horndog—or at least get you a date. (Even this guy.) But there's one problem: despite 50-plus years of research, scientists have yet to identify a single human pheromone responsible for triggering a sexual response from others.
That's not to say pheromones (chemical compounds that, when released by one animal and picked up by another, cause a biological response) don't exist. In the wild, their aphrodisiac effects are freakishly powerful: Give a female pig a whiff of androstenone, a pheromone produced by boars, and she'll present her rear, ready for action. Meanwhile, female silkworm moths secrete a pheromone called bombykol that can seduce a male to fly over from miles away and drop his pants.
Researchers have yet to see these kinds of single chemical cues work on human sexual arousal (uh, no shit, sounds illegal) but some studies suggest we do produce and receive pheromones, possibly from secretions in our endocrine glands—in places like our underarms, nipples, or genitals—or through general sweat or skin odor, says Charles Wysocki, a pheromone researcher at the Monell Chemical Senses Center in Philadelphia. And what we do know is that there's plenty of communication, possibly through hundreds of compounds at once—called an 'odor print'—which can influence mate selection. (Odor prints have too many compounds to be considered pheromones.)
In one study, when women were asked to sniff worn-in T-shirts from men and select the ones they wanted to socialize with, the women gravitated toward shirts from men who had a different group of genes that regulate the immune system (called the major histocompatibility complex, or MHC genes) than their own—a choice that would boost the immune system of their potential offspring. Meanwhile, another study found that men who smelled the shirts of ovulating (aka: fertile) women had higher levels of testosterone than men who smelled shirts worn by non-ovulating women. (Of course, whether or not those subtle cues might have an impact in the real world is up for debate—attraction is a complex beast, and humans also tend to rely on factors like good hair and a decent conversation before linking up.)
Ultimately, because our olfactory systems are so complex, what we know so far about pheromones has left researchers with more questions than answers. But the hunt is on: "There are a number of laboratories making headway into taking apart this complex set of chemical compounds," Wysocki says. He believes it's possible we could one day live in a world with bottled-up pheromones that aren't bunk. In the meantime, people can continue to be jealous of the sex lives of silkworm moths.
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