Commentary: Human pheromones
Biologists have long known that substances called pheromones influence sexual behavior in animals, but what of their effect in the human animal?
Pheromones are chemicals released from one animal that evoke a change in the behavior or hormone system of another animal. Scientists once regarded humans as immune to such influence. It's not that they saw such primitive mechanisms as beneath our dignity — rather, there was a scientific basis for their skepticism.
In most mammals, the nose contains a structure called the vomeronasal organ (VNO). This organ has receptors for pheromones that trigger hormone changes, readying an animal for sexual activity. Pheromone detection is distinct from smell; pheromones are odorless, and the VNO does not detect odors.