Pheromones are odorless chemicals that cause arousal and attraction in people. The pheromones that affect males and females are distinct from each other. There's a great deal of scientific research that suggests that pheromones really do work, and a number of perfume makers are incorporating pheromones into some of their fragrances. There are also several companies that sell synthetic pheromones on their own so you can add them to your own perfume. There's really no way to know for certain if a perfume contains pheromones short of a chemical analysis, but there are ways you can pick up a few clues.
Read the advertisements for the perfume. Generally, manufacturers use pheromones as a selling point.
Check the label and the package. Many will state that the perfume contains pheromones. Others have "pheromone" or some version of the word in their name.
Read the ingredients on the package label. Look for words beginning with "andro," specifically androstenol, androstenone and androstadienone. They are the three most commonly used pheromones in perfumes.
Observe your reactions to the scent. This is highly subjective, since it's difficult to say whether a subtle physical reaction is actually a response to the scent or to other stimulants, such as the presence of the person wearing the scent.