Pheromones, the sexual chemical signals which have been studied a great deal in animals.
What do we know about the sense of smell as it relates to sexuality? Over the past 30 years, there has been a good bit of attention to chemical signals which can be perceived by the sense of smell and cause a reaction in another individual of the same species.
Animals have a sense of smell which allows them to pick up a pheromone from the male and predictively will induce sexual behavior in the female. Animals which exhibit this kind of behavior have special sensory sections in their brain which humans do not possess. Therefore, it has been more difficult to identify the importance of this in human behavior.
Pheromones in humans are present in urine, semen, vaginal secretions, breast milk and possibly saliva. Much of the scientific study thus far has been directed toward axillary sweat. The secretions are odorless, but they are modified by bacteria, clothing, temperature and arm movements. Though not perceived, the chemical signal may be picked up by a woman.
One pheromone, androstadienone, seems to have the most robust effects on women. It improves mood and focus which are important for a woman’s sexual response and sexual satisfaction. It actually works on men as well.
There was a study with college students putting pheromones on the skin of the upper lip and nose or sniffed from jars. Rather high concentrations were used, and the subjects sometimes identified this as a musky smell such as sweat or a male roommate. The female participants showed increased mood for sex that was dependent on the dose and pre-exposure mood which was transmitted by a positive video tape. In the presence of a male partner, arousal and sexual response were enhanced.
More study is required about pheromones before any commercial claim of the arousing effects of androstadienone can be really endorsed scientifically. However, it seems that for couples who are having a bit of difficulty with their sexuality, the woman may want to try putting this on her upper lip. It may be worth doing your own experiment.
By the way, it is probably unrealistic to expect a man to put any of these compounds on himself and attract women in a bar or other dating situation despite claims of such victories on internet ads. Humans just do not have the super smell ability which allows this kind of response to pheromones.