How Do We Detect Pheromones?
Explore the vomeronasal organ (VNO)
For years, scientists believed that pheromone detection in humans occurred through the vomeronasal organ (VNO), located in the nasal cavity. Also called Jacobson’s organ—first identified in animals by Jacobson in 1811, but actually discovered by Kölliker in 1877 and observed earlier by Frederik Ruysch in 1703.
The VNO’s function, like that of the main olfactory epithelium, is to detect airborne chemical signals. However, it is not connected to the sense of smell. It plays a key role in chemical communication, especially for detecting sexual and social pheromones. Pheromones stimulate the VNO, triggering automatic, involuntary reproductive and social behaviors. VNO neurons are closely linked to brain regions controlling sexual and reproductive functions. The organ is particularly developed in predatory and ruminant mammals. It is thought to function in a more primitive, insect-like manner, while the main olfactory system evolved later with a different mode of operation. In short, the VNO is a supplementary chemosensory organ that directly converts volatile pheromone signals into physiological responses.
The VNO’s function, like that of the main olfactory epithelium, is to detect airborne chemical signals. However, it is not connected to the sense of smell. It plays a key role in chemical communication, especially for detecting sexual and social pheromones. Pheromones stimulate the VNO, triggering automatic, involuntary reproductive and social behaviors. VNO neurons are closely linked to brain regions controlling sexual and reproductive functions. The organ is particularly developed in predatory and ruminant mammals. It is thought to function in a more primitive, insect-like manner, while the main olfactory system evolved later with a different mode of operation. In short, the VNO is a supplementary chemosensory organ that directly converts volatile pheromone signals into physiological responses.
Sexual Nose
The VNO was discovered in humans in the 1930s but was considered a vestigial organ, only active in fetal life. For decades, no neural connections between the VNO and the brain were found, leading to the belief that these nerves had regressed during evolution.
However, in 1991, it was observed that skin compounds activate the human VNO differently in men and women, demonstrating sexual dimorphism. In 1996, a connection between the VNO and the pituitary gland was demonstrated. Stimulation with volatile compounds led to changes in luteinizing hormone (LH) and follicle-stimulating hormone (FSH) levels.
Womeroferins, specialized airborne compounds, stimulate the VNO and elicit gender-specific responses, while remaining undetected by the olfactory epithelium. This proves they act outside of conscious smell.
Anatomical and functional evidence now shows that the human VNO functions as a sensory organ, although less developed than in animals. Located in the nasal septum, this 0.2–2 mm structure has sensory receptors on both sides.
fMRI (functional brain imaging) studies have shown that when pheromones are inhaled, limbic brain regions—such as the hypothalamus, amygdala, hippocampus, thalamus, and prefrontal gyrus—are activated. These are distinct from areas stimulated by traditional odors, confirming that the VNO activates different brain pathways.
In one experiment, Androstadienone was directed exclusively to the VNO, bypassing the olfactory epithelium. Even though only 20% of subjects consciously detected the scent, many showed unconscious physiological reactions, proving pheromonal effects.
The VNO is therefore a unique receptor for specific pheromones like Androstadienone. It has been identified in adults, and vomeronasal ducts have been observed in about half the population. This suggests that only part of society may fully respond to pheromones, leading some to question their existence in humans.
Yet, research confirms that pheromones can also be perceived via the olfactory epithelium. The main and accessory olfactory systems work in parallel, processing sexual semiochemicals that influence mate selection and sexual behavior. Only about 5% of people are completely unable to detect pheromones.
Importantly, the VNO is not required for pheromone perception—even in animals—and it can also detect non-pheromonal signals. Therefore, no strict rule limits VNO function solely to pheromone detection. Both systems complement each other. As of 2010, research confirmed that the olfactory epithelium alone can perceive pheromones. A functional VNO is not necessary for pheromonal effects in humans
However, in 1991, it was observed that skin compounds activate the human VNO differently in men and women, demonstrating sexual dimorphism. In 1996, a connection between the VNO and the pituitary gland was demonstrated. Stimulation with volatile compounds led to changes in luteinizing hormone (LH) and follicle-stimulating hormone (FSH) levels.
Womeroferins, specialized airborne compounds, stimulate the VNO and elicit gender-specific responses, while remaining undetected by the olfactory epithelium. This proves they act outside of conscious smell.
Anatomical and functional evidence now shows that the human VNO functions as a sensory organ, although less developed than in animals. Located in the nasal septum, this 0.2–2 mm structure has sensory receptors on both sides.
fMRI (functional brain imaging) studies have shown that when pheromones are inhaled, limbic brain regions—such as the hypothalamus, amygdala, hippocampus, thalamus, and prefrontal gyrus—are activated. These are distinct from areas stimulated by traditional odors, confirming that the VNO activates different brain pathways.
In one experiment, Androstadienone was directed exclusively to the VNO, bypassing the olfactory epithelium. Even though only 20% of subjects consciously detected the scent, many showed unconscious physiological reactions, proving pheromonal effects.
The VNO is therefore a unique receptor for specific pheromones like Androstadienone. It has been identified in adults, and vomeronasal ducts have been observed in about half the population. This suggests that only part of society may fully respond to pheromones, leading some to question their existence in humans.
Yet, research confirms that pheromones can also be perceived via the olfactory epithelium. The main and accessory olfactory systems work in parallel, processing sexual semiochemicals that influence mate selection and sexual behavior. Only about 5% of people are completely unable to detect pheromones.
Importantly, the VNO is not required for pheromone perception—even in animals—and it can also detect non-pheromonal signals. Therefore, no strict rule limits VNO function solely to pheromone detection. Both systems complement each other. As of 2010, research confirmed that the olfactory epithelium alone can perceive pheromones. A functional VNO is not necessary for pheromonal effects in humans
Pheromones Act on the SUBCONSCIOUS
Although the VNO is a group of specialized sensory cells located in the nose, it has nothing to do with the sense of smell[^11]. The pheromones that stimulate it at low concentrations are odorless substances. They are not detectable by the traditional olfactory sense.
There is a huge difference between the sense of smell and the other senses. Olfactory stimuli reach the cerebral cortex bypassing the thalamus (a group of cells responsible for rational thinking). Additionally, unlike the senses of sight, hearing, and touch, they are processed in the right hemisphere of the brain, which is responsible for emotional control. Olfactory centers are located in the hypothalamus, the oldest evolutionary part of the brain, responsible for reflexes, addictions, desires, and sexual activity. Olfactory signals — including those received from the VNO — are subject to very limited rational control. Information sent from the nasal organs is not filtered in any way. Therefore, the mucous membrane of the nasal epithelium is the only place where the central nervous system makes direct contact with the external world. Before we even become aware that we are smelling something, our subconscious has already responded to the signal.
The most important fact is that thanks to the VNO, the effects of pheromones are perceived completely subconsciously. For this reason, the VNO is often referred to as the sixth sense. Like the G-spot, it serves as a channel for intense brain stimulation.
There is a huge difference between the sense of smell and the other senses. Olfactory stimuli reach the cerebral cortex bypassing the thalamus (a group of cells responsible for rational thinking). Additionally, unlike the senses of sight, hearing, and touch, they are processed in the right hemisphere of the brain, which is responsible for emotional control. Olfactory centers are located in the hypothalamus, the oldest evolutionary part of the brain, responsible for reflexes, addictions, desires, and sexual activity. Olfactory signals — including those received from the VNO — are subject to very limited rational control. Information sent from the nasal organs is not filtered in any way. Therefore, the mucous membrane of the nasal epithelium is the only place where the central nervous system makes direct contact with the external world. Before we even become aware that we are smelling something, our subconscious has already responded to the signal.
The most important fact is that thanks to the VNO, the effects of pheromones are perceived completely subconsciously. For this reason, the VNO is often referred to as the sixth sense. Like the G-spot, it serves as a channel for intense brain stimulation.
So how can one believe in the effect of something that doesn’t even have a smell?
A strong argument is the fact that 61% of people who tried branded pheromone products once became regular customers. Out of the last 50,000 orders placed with the manufacturer, only 18 were returned.
Fact:
It’s pheromones that enable a female moth to attract males from great distances. Pigs can find truffles underground because this type of fungus produces a pheromone similar to the scent of a male pig. Ants use pheromones to mark locations where they’ve discovered food, allowing them to later lead others directly to the source. It’s also been proven that male butterflies will attempt to mate with any object soaked in female pheromones.
The content of the website is based on independent scientific research. The complete bibliography can be found here.
Further Reading:
http://www.cf.ac.uk/biosi/staff/jacob/teaching/sensory/pherom.html
http://serendip.brynmawr.edu/bb/neuro/neuro99/web3/Bernstein.html
http://en.wikipedia.org/wiki/Vomeronasal_organ
Keywords: VNO, vomeronasal organ, Jacobson’s organ, vomeronasal, sixth sense
http://www.cf.ac.uk/biosi/staff/jacob/teaching/sensory/pherom.html
http://serendip.brynmawr.edu/bb/neuro/neuro99/web3/Bernstein.html
http://en.wikipedia.org/wiki/Vomeronasal_organ
Keywords: VNO, vomeronasal organ, Jacobson’s organ, vomeronasal, sixth sense
