In many other animals, smells are an important signaling mechanism that can indicate ownership and trigger mating. When chemicals have this effect, they’re called pheromones. Essentially, pheromones act like hormones that travel out of the body. An individual secretes pheromones, they waft through the air, and they trigger a behavior in someone else.
Despite some top-flight scientific studies and many teenage fantasies, no one has ever discovered a chemical in humans that acts like a pheromone. However, there are plenty of tantalizing possibilities. Some provocative scientists suggest that pheronomes may underlie the mysterious chemistry of mate selection and explain why we tend to choose lovers who have distinctly different immune systems from our own. Others wonder if pheromones can explain why women living together may begin to menstruate on the same schedule. Both of these phenomena are highly disputed and might add up to nothing more than hot air. However, the possibility of mysterious chemicals controlling our destinies is thought-provoking. It’s also enough to make you think twice before reaching for the deodorant stick.
Source of Information : Oreilly - Your Body Missing Manual