Androstenone is produced by humans, truffles, and pigs. Male pigs or boars to be exact, no doubt this is the reason for the untrue though persistent "pig pheromone in the other guy's cologne" claims that circulate on the internet. This is simply propaganda used by some pheromone companies to scare their customers into only using their products.
Androstenone is found in both men and women. However, it is considered to be a male pheromone as men produce much larger quantities of it. The presence of Androstenone signals high testosterone, sex drive, aggression, and dominance. Androstenone in large amounts can be very intimidating for both sexes and is no doubt the number one alpha pheromone (either alpha male or female) Wearing Androstenone is known for inducing greater respect for the wearer from both sexes.
Around one half of the population cannot smell Androstenone. Of those who can, a percentage will tell you that it has a woodsy urine smell or is sweat like , while a smaller percentage will say that it smells like vanilla or has a sweet smell. Why the vast discrepancy in scent identification? Researchers at Duke University believe that it has to do with genetics. These same researchers say, "In human females, studies show it may cause arousal, sweating and a surge in stress hormones. The increase in the stress hormone Cortisol has lead some pheromone researchers to deem androstenone as a female repellent instead of an attractant. Leading to nice guys running from androstenone products. I guess they have not taken into account that further research has shown that the fastest way for women to lower Cortisol levels was to have sex. We may now better understand why the bad boys get the girls, and nice guys pay the bills.