In other species, sexual activity is a matter of the right smell and unlimited access. Pheromones are what make a dog in heat irresistible to potential mates across long distances. Pheromones are also what cause a single female palm sawfly in a cage to draw more than 2,000 mates a day from miles away. And, in swine, male pheromones cause females to instantly assume a posture for mating.
Pheromones too are a critical factor in sexual behavior and reproduction in humans, even though the chain of events and stimuli that lead to sexual activity is far more complex. Men naturally produce pheromones that send important chemical messages to prospective mates. Women receive and process these messages through either their olfactory system (which processes smells), an accessory system called the vomeronasal organ (VNO), or both of these. Scientists aren’t yet sure how active the VNO is in humans, although it is highly active in other species.
The chemical signals contained in pheromones bypass higher levels of conscious thought and proceed immediately to the hypothalamus, which is a brain structure connecting the nervous system with the hormone-producing endocrine system. In women, male pheromones stimulate the autonomic nervous system, increasing heart rate and blood pressure, trigger the release of cortisol, which prepares the body for stress, and prompt the production and release of the female sex hormones, estrogen and progesterone.
Male pheromones are also associated with feelings of calm, relaxation, and alertness in women, as well as being linked to more positive visual evaluations of unfamiliar men. Last but not least, the chemical signals of pheromones help women select mates with whom they are the most biologically compatible.
These effects have been proven in laboratory studies using specially prepared extracts that contain pure male pheromones. However, even using special concentrations of pheromones, any fragrance is either masked by another substance or imperceptible to women. In most studies, if they could smell anything at all, women had no idea they were smelling male pheromones.
This is important to note because, while they’re typically sold in fragrant formulas, you might not be able to detect a scent that you can attribute to pheromones. And women don’t need to be able to smell something different about your fragrance to be affected by pheromones. It may well be the lack of anything discernibly different about pheromone fragrances that leads to some skepticism about their value.
Most men aren’t consciously aware of the smell of their natural pheromones, either. This is primarily because, at least in the Western culture, we tend to bathe frequently enough that pheromones don’t attain a highly concentrated-thus smellable-form. In fact, suing antibacterial soaps and deodorants can lessen the amount of natural pheromones on your skin.
To amplify the effects of pheromones, men need to either bathe less often or apply a fragrance that contains one or both of the best male pheromones, androstadienone and androstenol. Since human sexual behavior also depends on visual and verbal cues, context, social norms, and other complex factors, the second option is far more likely to be successful in the world of dating.