A pheromone is a chemical that an animal produces which changes the behavior of another animal of the same species. Evidence for the existence of pheromones in humans is limited.

Some describe pheromones as behavior-altering agents. Many people do not know that pheromones trigger other behaviors in the animal of the same species, apart from sexual behavior.

Hormones usually work internally, and they only have a direct effect on the individual that is secreting them.

Pheromones, unlike most other hormones, are ectohormones. They are secreted outside the body, and they influence the behavior of another individual.

Pheromone attractionShare on Pinterest
Do pheromones play a role in human attraction?

Pheromones refer to chemical signals that can trigger behavioral responses in members of the same species. Many people may associate pheromones with sexual arousal and mating. For example, one of the first pheromones researchers identified was bombykol. This is a pheromone that female silkworm moths secrete to attract males.

However, these chemicals can trigger many types of behaviors. For example, in mosquitos, pheromones can influence:

  • mating behaviors
  • where they lay eggs
  • finding food
  • finding hosts

In insects, research also highlights that pheromones play a role in aggregation. This behavior can be helpful in many ways, as it can help insects to coordinate feeding and mating activities, as well as provide potential protection against predators.

As such, it is possible to use pheromones in insect control. People can use them as bait to attract males into a trap, prevent them from mating, or to disorient them.

Evidence also suggests that pheromones play a role in the behavior of many mammals. However, experts note that the pheromone system of insects is much easier to understand than that of mammals, which do not have simple stereotyped insect behavior.

Researchers believe that mammals detect pheromones through an organ in the nose called the vomeronasal organ (VNO), or Jacobson’s organ. However, there is a long-standing debate on the presence and functionality of the VNO in humans.

Although many proponents may suggest that human pheromones exist, most proper, well-controlled scientific studies have failed to show any compelling evidence. For example, there is no compelling evidence to suggest that androstenol or androstenone are effective as human pheromones.

Gustav Jäger, a German doctor and hygienist is thought to be the first scientist to put forward the idea of human pheromones, which he called anthropines. Later in the 1990’s, Dr Martha McClintock proposed “the McClintock effect“, which describes the synchronization of menstrual cycles due to unconscious odor cues. However, recent analyses of McClintock’s study and methodology have questioned its validity.

Overall, evidence for the existence of pheromones in humans is weak, but it cannot be ruled out entirely. If human pheromones are ever found, their effects are probably very subtle.

Older research suggests there are four main types of pheromones:

Share on Pinterest
Moths use pheromones to communicate, but what about people?
  • Releaser pheromones: These elicit an immediate response, and the response is rapid and reliable. They are usually linked to sexual attraction.
  • Primer pheromones: These take longer to get a response. They can, for example, influence the development or reproduction physiology, including menstrual cycles in females, puberty, and the success or failure of pregnancy. They can alter hormone levels in other beings.
  • Signaler pheromones: These provide information. They may help a birthgiver to recognize their newborn by scent. Signaler pheromones provide a genetic odor print.
  • Modulator pheromones: They can either alter or synchronize bodily functions. They are usually found in sweat. In animal experiments, scientists found that when placed on the upper lip of females, they became less tense and more relaxed. Modulator hormones may also affect a person’s monthly cycle.