How it works
Pheromones are chemicals that act as signals between members of the same species. Scientists have known for a long time now that most animals give off pheromones. Ants send off pheromones when one ant has died and his body needs to be removed from the colony. Male pigs give off pheromones that signify the desire to mate. Historically, most scientists scoffed at the idea that humans use pheromones to signal important behaviors to each other - they figured that humankind had evolved to a point where we used our minds to decide when and with whom to mate. Recent studies have shown, however, that we are not so far removed from our animal instincts as we thought.
Since 1703, scientists have known about an organ in the nasal cavity known as the vomeronasal organ or VNO. They assumed it was an evolutionary relic - an organ that humans no longer used. However, in the last 25 years, scientists have discovered that the VNO is the receptor for pheromones. The VNO gives us a sort of "sixth sense;" we can't see, smell, hear, or feel pheromones. As a matter of fact, we cannot consciously perceive pheromones at all, though experiments prove that they can work.
For example, it has been discovered that when the underarm sweat of women in different menstrual phases is placed under the noses of female subjects, the length of these subjects' own cycles is significantly altered. Underarm sweat has been shown to have a pheromone component - androstenol. This explains why females living in close quarters, such as college dormitories, often have synchronized cycles.
Men and women exposed to pheromones claimed that they felt self-confident, attractive, and romantic. In tests of pheromone effectiveness, it has been found that 74% of subjects testing a pheromone product experienced an "increase in hugging, kissing, and sexual intercourse." Also interesting, foods that have been known for centuries to have aphrodisiac qualities, such as truffles and oysters, have recently been found to chemically correspond to human pheromones. Still not convinced?
ABC News conducted an experiment of their own to see if pheromones really do work. They took a set of identical twins and applied a pheromone oil to one twin and plain, old witch hazel to the other one. They took the twins to a bar and had them switch places throughout the night so no one would realize they were 2 different people. The results were amazing! 30 men approached the twin wearing the pheromones while only 11 men approached the sister wearing witch hazel. The use of pheromones appears to have tripled the success rate! | 
