Imagine an invisible, undetectable force that's powerful enough to override your sense of reason yet draws you to someone with an almost animal passion. These aren't Cupid's mythological arrows, but real shots of human pheromones. Scientists have been researching for years whether or not humans, like other animals, exude these secret scents, with attention focused on a small organ composed of two small pits a few centimeters up the nose.

Biologists describe pheromones as "smellprints" supposedly as unique to each of us as our fingerprints. Smell is the most primitive of human senses and, unlike sight and touch, travels a direct route to the brain's limbic lobe where it can provoke an emotional reaction that can, quite literally, be a turn-on.

There's no doubt that pheromones underlie sexual and other types of behavior in animals, but given the complex human psyche, can these invisible lust signals be all you need for love? The scientific verdict is pending, but an increasing body of evidence suggests that the chemistry of sexual attraction and arousal is more nature than nurture and quite beyond our control. Not so far-fetched a notion considering how often we speak — and sing — of sexual chemistry.

Love or lust — the question hasn't stopped the fragrance industry from attempting to cash in on the accumulating knowledge about pheromones by producing synthetic versions of these elusive chemicals. True, the new fragrances aren't billed as aphrodisiacs. Instead, they're advertised as mood-enhancers designed to help you relax and shed your inhibitions.

While there's absolutely no proof that they can deliver on any kind of erotic promise, the new pheromone perfumes are selling briskly, even to repeat customers. Which may prove, yet again, that when it comes to aphrodisiacs, nothing trumps the power of suggestion.