It is controversial whether or not humans convey specific compounds within their body odours which can potentially affect the physiology and behaviour of others. Such compounds are called pheromones and have been discovered in many other species, including mammals. It has been suggested that humans might have a special organ within their nose that can transmit such chemosensory information. However, the evidence for this organ is highly questionable. In any case, the main olfactory system is a highly diverse system, capable of transmitting pheromonal information.
So far, no single substance has been found that acts as a chemical messenger for erotic attraction. On the other hand, studies investigating the pheromonal properties of natural complex body odour have proven that it does deliver information about the sender and that it has an effect on the physiology and likely behaviour of other humans. Its significance for human mating preferences probably lies not in driving them to choose the right mate but rather in warning them not to choose the wrong one.