What role Pheromones actually play in sexual attraction

Human pheromones are chemical molecules released in humans to trigger a response to or to elicit specific behavioural response or hormonal changes from someone. These signaling molecules are contained in body fluids such as urine, sweat, specialized exocrine glands and genital mucous secretions.

Sex pheromones

Pheromones are broadly divided into two classes:

1. Releaser pheromones that produce short-term behavioural changes and act as attractants or repellents
2. Primer pheromones that produce long-lasting changes in behaviour or development via activating the hypothalamic–pituitary–adrenal axis.

Pheromones are differentiated into aggregation pheromones, alarm pheromones, epideictic pheromones, territorial pheromones, trail pheromones, information pheromones and sex pheromones.

The claimed male human pheromone that attracts a woman is androstadionone present in sweat. It exerts a positive effect on her mood, cognition and heightens sympathetic nervous system arousal. Also, the claimed unknowingly secreted female pheromone that attracts a man is androstenol. Axillary glands and vaginal secretions are main sources of pheromones in females.

Sense of smell is important as an arousal system. It is reported that nasal receptors near the entrance of the nose, called vomeronasal organ (VNO) have the strongest reaction to air containing pheromones, transferring it to stimulate the hypothalamus with a signal of attraction, sexual desire, arousal etc. The glands that produce odors are located everywhere on the skin, but concentrate in six areas: axillae, nipples, pubic, genital and circum-anal regions, the circum-oral region, lips, eyelids and the outer ear.

Thus pheromones are species-specific chemical messages that cause others to exhibit unlearned behaviors and physiological responses. Olfaction as a sensory modality in humans has become less important subsequent to the use of language and mails and perhaps even more with the use of perfumes and deodorants to disguise our body odours. Emerging evidence shows that it may play a far more important role than we suppose and it may be involved in hormone regulation, behaviour and in determining when, how and with whom we choose to reproduce.