Definition of Pheromone:
: a chemical substance that is usually produced by an animal and serves especially as a stimulus to other individuals of the same species for one or more behavioral responses


Human Pheromones
Pheromones in humans are postulated to be produced by the apocrine glands. Apocrine sweat glands produce sweat that contains fatty materials. These glands are mainly present in the armpits and around the genital area and their activity is the main cause of sweat odour, due to the bacteria that break down the organic compounds in the sweat from these glands. The apocrine glands become functional after reaching puberty which, some believe, could contribute to people developing a sexual attraction for others at that time. Pheromone detection has also been proposed to be the reason why a person can sense "chemistry", or feel an instant attraction or dislike when first meeting someone.

Researchers at the University of Colorado have found that pheromones are detected through the Vemeronasal Organ (VNO) in the nose. The VNO functions as the distinct sensory apparatus that detects pheromones. All people they examined had two small holes on both sides of the hard divider in the nose. The holes are found just inside the opening of the nose. A group of clear cells lies just behind these holes. These cells are similar in appearance to nerve cells . These scientists have concluded these cells are responsible for detecting human sex pheromones. The pheromones then transmit a signal to the hypothalamus in the brain (the brain's center of emotions), sending a chemical message of sexual attraction.
Pheromones are believed to be detected on an instinctual, subconscious level. In other words, you don't know that you're receiving them, but you are.

On March 21, 2002, ABC News reported that scientists at San Francisco State University found that women who had pheromone added to their perfume reported a more than 50% increase in sexual attention from men. The study, which was published in the Journal of Physiology and Behavior, found that 74% of the women saw an overall increase in 3 or more of the following socio-sexual behaviors: frequency of dates, kissing, heavy petting and affection, sexual intercourse, and sleeping closer to their partner.

Scientists have identified the chemical, androstenone, as the male pheromone.In addition to increasing the animal magnetism of a man, androstenones bring about an increase in the luteinizing hormone (LH) in a woman who happens to be nearby – thereby causing a woman to have a heightened sexual responsiveness to a man.

The compound, copulin, on the other hand, has been identified as the female pheromone. When optimized, copulins bring about a testosterone surge in men, thereby causing a man to have a heightened sexual responsiveness to a woman.

Not all commercially available androstenones and copulins are created equal. Pheromone vendors that carry optimized pheromones for men and optimized pheromones for women are rare.