Do Human Pheromones Exist?

Pheromones are often used to explain why you’re attracted to someone unexpected, or how you tolerate your partner’s very particular post-run funk, but abhor anyone else’s.

Except there’s no proof that they exist. Though pheromones are a well-accepted part of the cultural love lexicon, they don’t have much by way of scientific backing. Not in human beings, at least. Pheromones certainly play a role for ants, who use them to navigate the world, and for mice, who use them to separate friend from foe. They’re a way for animals to communicate with one another using chemical signals. One biotech startup is even using pheromones to control nematode behavior (a type of microscopic worm) for agricultural applications. But when it comes to people, the evidence is decidedly more shaky. We don’t really know whether human pheromones exist at all, let alone why they might make bachelor A more attractive to us than bachelor B.

That’s not to say that scientists—and marketers—haven’t tried to convince us otherwise. Eager to bottle up a love potion to sell to hapless singles, there are ample dubious studies on the topic, often sponsored by perfume and shower gel companies. Unsurprisingly, the research is often non-replicable and of questionable quality. Smelly T-shirt tests may be fun, but they don’t tell us much about how we work as organisms, let alone what chemicals might be doing the work.

Rigorous testing has shored up even more uncertainty on the topic. A double-blind study by researchers from the University of Western Australia, performed in 2017, tested the effect of two chemicals on 94 people. The first, androstadienone, is found in male sweat and semen; the second, estratetraenol, is found in women’s urine. Both are among the most likely candidates for human pheromones.

Over multiple days, the subjects—all white and heterosexual—were exposed to these two scents, then asked to participate in two tests. In the first test, they were shown gender-neutral facial images and asked to guess the person’s gender. In the second, they were shown a selection of people’s faces and asked to rate their attractiveness, as well as how likely they’d be unfaithful. (The participants did not know that they were being tested on anything related to pheromones.) The result? Contrary to researchers’ initial hypothesis, neither chemical seemed to have any effect whatsoever. 

However, that doesn’t mean that human pheromones are a Harlequin romance fantasy. It might just be that we haven’t found the right ones yet. 

Tristram Wyatt, a zoologist from the University of Oxford, thinks that we’re not approaching the problem in the right way. To really understand human pheromones, he says, we need to start approaching humans as if we were any other animal, rather than through surveys or other kinds of self-reporting data, which are ripe for misinformation: “There are no shortcuts.” 

Wyatt suggests looking beyond questions of sexual attraction to human-produced chemicals that queue other kinds of communication. “One of the most promising human pheromone leads is a nipple secretion from the areola glands produced by all lactating mothers, which stimulates suckling by any baby, not just their own,” he writes.

That’s not quite as sexy. But then again, neither is a sweaty T-shirt.