… it is the molecular biology common to all species that assures us olfaction and odor receptors provide a clear evolutionary trail, which can be followed from unicellular organisms to insects to humans.
Pheromones are like food odors. Not every food is equally appealing. But we can enhance individual appeal with pheromones just like we can spice up the appeal of food.
The prenatal migration of GnRH neurosecretory neurons allow human pheromones to effect GnRH pulsatility, which modulates the concurrent maturation of the neuroendocrine, reproductive, and central nervous systems, thus influencing the development of human reproductive sexual behavior and other behavior.
Recent discoveries show that human pheromones are signals that are processed by cells in our main olfactory system.