Follow Your Nose: The Science Behind Love, Sex, and Scent

In honor of Valentine's Day, we're spending the week debunking myths and lies about romance. Read the rest of our "Love is a Hoax" coverage here.

Clean, unclean, even that little kick of sweaty pits, can be sexy as hell. But some people, it's like they've been rolled in monosodium glutamate and sprinkled with Pringles—you just can't get enough.

I've always thought that's when I've really liked someone: When I've purposefully face planted their dirty laundry and put my nostrils to work like a Dyson. And I blame pheromones.

Pheromones are an odourless chemical that plants, fungi, insects, and animals secrete, specifically in the case of humans through our sweat, tears and urine. In the animal and plant kingdoms, it's widely accepted that pheromones are released to communicate a message, to signal to others of the same species sexual desire and "optimal fecundity" (hot). Pheromones aren't actually smelt by the nose but instead are detected by the vomeronasal organ in the nasal cavity, which links to the olfactory bulb and in turn pings a memo up to the brain.

In humans, some believe that these chemical messages are received by the part of our brain known as the hypothalamus, the bit of our gray matter where oxytocin is produced—also known as the "love hormone," it's responsible for social bonding, maternal affection, and sexual pleasure.

In terms of sexual attraction, though, the theory goes that the chemical signal that we involuntarily waft over potential mates is either interpreted as hot-to-trot or absolutely fucking disgusting. What's the point, you ask? Well, some scientists believe that those with a mutual addiction to each other's smell have different immune system profiles, and therefore, if they have babies the combined efforts of their unique gene codes are better equipped to fend off infection and disease. In short, they're evolution's genetic jigsaw, and it's the basis for the rise of pheromone parties and other blind date nights that involve hopeful singles sniffing each other's armpits or used T-shirts to find their one true love.

However, the thing with human pheromones is that nobody is quite sure what role they play in our behaviour, if any at all. In fact, some scientists even dispute their existence in humans. Though proven to be a huge player in the laws of attraction in the studies of botany, zoology and entomology (I'm looking at you, saucy little silkmoth), the human sex pheromone is a contentious issue. In relation to attraction and fertility, there is both supporting evidence for the theory and ardent criticism against it—and the functional role of the human vomeronasal organ is still under academic scrutiny.

Indeed, to celebrate their 125th anniversary, Science magazine listed "Do pheromones influence human behavior?" as one of the "compelling puzzles and questions facing scientists today" (alongside humdingers such as "Why do we sleep?", "What causes ice ages?", and the B-movie-in-waiting, "Why doesn't a pregnant woman reject her fetus?").

However, there's evidence enough for many to market this magnetic sex smell to make money. Since the 90s, pheromone love potions—in the form of oils, perfumes and sprays—have been sold online and in sex shops; each one a formula for attracting that perfect mate.

Dr. Winifred Cutler is the president and founder of the Athena Institute for Women's Wellness and self-styled "co-discoverer of human pheromones." Since 1993, Cutler's Athena Pheromone 10:13™ (for women) and Athena Pheromone 10X™ (for men) have been the benchmark of pheromone products, rivalling brands such as Pure Instincts, JO Pheromone, and Booty Parlor Flirty Little Secret Perfume Oil.

Billed as "unique cosmetic fragrance additives," Dr. Cutler told Broadly that Athena products contain "synthesized human pheromones that are a chemical copy of the natural pheromones" produced by the respective body of a sexually active female and male in their mid-20s.

Pertaining to the science of attraction then, what does Athena Pheromones impart to its users? "Nothing directly," Dr. Cutler said. "The effects are not on the user but on members of the opposite sex she [and he] has social contact with. Neither 10X nor 10:13 is an 'aphrodisiac' or a 'drug.' They are cosmetic fragrance additives that increase the wearer's attractiveness to the opposite sex."

Still, could I spray some of the product on me, walk into a club, and meet a potential boning partner in a matter of minutes? No. Firstly, as with all other pheromone potions on the market, Athena's products aren't sprays. They're mostly oils that are dabbed on your face, preferably above your upper lip. But, used daily as directed, Dr. Cutler claims that 10X is proven to increase "affectionate behaviour from women." She warned, however, that the product "is not magic and won't turn an unkempt lout into an irresistible ladies' men."

As for 10:13, that "basically tames responding men to behave in a more courtly and genteel manner" (whatever that means), and Dr. Cutler even claims that anecdotal reports from businesswomen reveal that 10:13 increases their sales in face to face transaction.

Watch: Casting Curses and Love Spells with the Most Powerful Witches in Romania

Dr. Cutler backs up most of her claims with several peer-reviewed studies, and it's worth noting that she has presented seminars on pheromones at the American College of Obstetricians and Gynecologists, the American Society for Reproductive Medicine, and the American Psychiatric Association.

However, her work is controversial. One study shown to me had a sample size as small as 36 subjects and another, 38. She also parted ways with one of her former colleagues, Dr. George Preti, over the role that pheromones might play in human attraction. "There was no proof to suggest the effects she was talking about," he told Salon.

When asked about the academic studies that run counter to her work, Cutler replies, "The interesting thing about science is that the failure to find a phenomena cannot prove it does not exist—only that the research was not able to design a study that proved what he [or she] was looking for."

Putting the controversy of pheromones to one side, there's no denying the power of scent, particularly for females. A 2002 study titled The importance of smell for women revealed that body odor outranked a man's looks, voice, and social factors, such as money or ambition, when selecting a lover.

Sex toy brand Lelo's scented vibrator from 2015 is a prime example of how scent and sex can go together—although you may not be a fan of its range, which includes a not-so-sexy lavender and manuka honey option. Lelo's resident sex and relationship expert, Vanessa Marin, told Broadly that our sense of smell (which she says is 10,000 times more precise than taste) doesn't just affect our sexual pleasure, but that sexual pleasure also affects our sense of smell.

"When we orgasm, our body releases the hormone prolactin, which stimulates the brain to produce more neurons in the olfactory bulb, making our sense of smell more keen," she said, explaining once and for all the appeal of that post-shag fug—pheromones or not.