Gosh, it would just be so nice if we could actually make someone else be attracted to us — at least, it would be a lot easier than having to go on charm and self-confidence and all that. Which is where the popular idea of instant-attraction pheromones comes in. As for the the actual science behind pheromones, research says you probably can't just spritz yourself with them and expect a gaggle of admirers to appear. At their most basic level, pheromones are simply chemicals that are released by one animal and picked up by another, producing changes that benefit both parties. George Preti, PhD, of the Monell Chemical Senses Center, says one of the biggest mistakes we make in talking about pheromones is thinking they're all the same. "Like snowflakes," he says, "they come in many different varieties." One variety is the primer pheromone. These cause slow changes in the endocrine system of the animal on the receiving end, which affect how their hormones control a wide variety of bodily functions. In mice, this may mean they'll mature at an accelerated rate. In ants, primer pheromones help regulate the reproduction patterns in their colonies. The hormones we usually talk about in the context of love are releaser pheromones, which cause the receiver to react immediately. When female pigs in heat get a whiff of a male pig's androstenone, they get into a mating stance. Interestingly, recent research suggests androstenone may also be used to calm down an unruly dog. Perfumes advertised to have pheromones in them (like these beauties) tend to use pig pheromones such as androstenone, but there's no conclusive evidence that we react to these bottled scents in the same way. And, our sense of smell is so profoundly influenced by our experiences that every individual has different associations with different scents, meaning there's no guarantee two people will react the same way. Not exactly ideal if you're trying to create a pheromone formula that works for everyone. The other issue is that, in non-human mammals, pheromones are processed by the vomeronasal organ. Humans do have a vestigial version of the VNO, but most scientists agree that it lacks functioning sensory cells and, therefore, doesn't actually work. Instead, there's some controversial evidence to suggest that the little-known "cranial nerve zero" (also the name of our nü metal band) may have taken over that job. However, there's still debate about its exact function — or whether it even has one anymore. Smell certainly does play a role in attraction, though it may not necessarily be through pheromones, and it certainly isn't as dramatic as we might prefer to think. Instead, there is some evidence in mice to suggest that we're attracted to the B.O. of those who are immunologically complementary to us. Supposedly, this is because those smells may be produced by certain compounds binding to cells that also play a role in fighting off illnesses. But, you may have noticed that humans are complex, and there are a lot of complicated factors determining your level of attraction to someone else. Whether or not a person smells nice certainly isn't everything. Unfortunately, that means you won't be buying attraction in a bottle anytime soon. Maybe that's for the best. If you want to know even more about pheromones, check out the American Chemical Society's new Reactions video below.