The Chemistry of Lying


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What happens when you lie? Do you start to sweat or get a little nervous? Does your heart begin to beat a little faster? Lying is the act of being deceptive or untruthful. It has become apart of everyday life for most people, with the average person telling at least one lie a day. But few people know what happens inside their body when they lie and how that reaction relates to chemistry.

I chose to do my project on the Chemistry of Lying because lying is something that humans encounter on a daily basis. I wanted to know what happened inside the body when you lie and what causes your heart to beat faster or that nervous feeling in your stomach. Through my research, I also hoped to understand what drives people to lie so frequently. It was an interesting and rather abstract topic that I had not thought much about in the past.

    With deception occurring in thirty percent of one-on-one conversations a person has in a week, it is easy to see how lying affects most people's lives. For me personally, one of my biggest pet peeves is being lied to. Lying is not something that can be avoided easily but knowing more about the hows and whys of lying will hopefully help us to understand we are so prone to deceiving one another.

Composition of ...

Catecholamines are the main hormones released in the body when you lie because these hormones are responsible for reactions that spawn from stress. All catecholamines contain a main catechol group, C6 H4(OH)2 .

The main catecholamines are:

  • Epinephrine (Adrenaline)- C9H13NO3

  • Norepinephrine- C8H11NO3

  • Dopamine- C8H11NO2

Main Chemicals, Compounds, Components

The two main components of lying are the catecholamines, epinephrine and norepinephrine.

  • Epinephrine, C9H13NO3, otherwise known as adrenaline, is the hormone responsible for the reactions that happen to body when a person becomes stressed. These reactions include increased heart-rate, muscle tenseness, increased blood pressure and respiration, and vasoconstriction. Epinephrine essentially prepares the body for stressful or harmful situations. It is produced by the adrenal medulla using the two amino acids phenylalanine,C6H5CH2CH(NH2)COOH, and tyrosine, C9H11NO3. First dopamine is produced which is then converted into norepinephrine and then into epinephrine through a series of reactions. It is then stored in the chromaffine cells of the adrenal medulla. Epinephrine is released into the bloodstream when the sympathetic nervous system is stimulated by something that causes a person to feel stressed. The adrenocorticotropin hormone is also used in the process of stimulating the adrenal gland to release epinephrine.  Adrenaline or epinephrine is produced in the body because it is an important part of the body’s ability to survive. It can save someone’s life even in the most stressful of situations. Although lying usually is not life-threatening, epinephrine is the force behind the telltale symptoms of lying like sweating and elevated heart-rate.

Norepinephrine, C8H11NO3, is another “fight or flight” hormone that is released when the body undergoes stress. It is also produced in the adrenal medulla and is created in the same way that epinephrine is, through the transition of amino acids into hormones. Once norepinephrine is produced, it is then stored in the synaptic vesicles until stimulated to release. This release occurs when the body begins to feel stressed and is done so to prepare the body for a harmful situation by providing protection to key organs and functions of the body. When this hormone is released, it binds to adrenergic receptors in order to carry out its many duties. Norepinephrine triggers the releases of glucose into the bloodstream and causes an increase in: blood pressure, heart-rate, mental awareness, and respiratory rate.  It also acts as an anti-inflammatory of the brain and draws blood away from some organs to prepare the body for the situation it faces.

Chemistry's Role

Epinephrine and norepinephrine are two hormones that are naturally produced within the body through a series of reactions. Both derive from the same two amino acids, phenylalanine and tyrosine, which are the building blocks for catecholamines. The process from the creation of these two hormones is this:

  • Epinephrine-

    • Phenylalanine →Tyrosine→L-DOPA→dopamine→norepinephrine→epinephrine

Tyrosine is oxidized into L-DOPA; oxidation is a chemical reaction that occurs when a substance is in the presence of oxygen. From there, L-DOPA is decarboxylated into dopamine; decarboxylations is the chemical reaction that removes carboxyl group, COOH, and results in the release of carbon dioxide. Dopamine is then oxidized into norepinephrine, and norepinephrine is methylated into epinephrine. Methylation is the substitution of an atom or group by a methyl group, CH3.

  • Norepinephrine-

    • Phenylalanine →Tyrosine→L-DOPA→dopamine→norepinephrine

The same process occurs during the creation of norepinephrine, but it stops before methylation occurs.

Both of these hormones can be created synthetically in the lab for pharmaceutical purposes. The process used to artificially create these hormones is extremely similar to that of which occurs inside the body, but production may vary by company and/or the medication’s purpose. One common example of the medical use of epinephrine is in the Epipen.

These two hormones do not result in the man-made production of lying. They are just key factors in the emotions that are felt while lying. These two hormones, individually, however can result in man-made products like medication.

Background Research

Lying is a very common occurrence in our everyday lives, and so naturally we as humans seek to know the truth. There are very few known ways of detecting whether someone is lying, and one of those ways is through the use of polygraph testing. A polygraph measures the reactions that come from your sympathetic nervous system like blood pressure and pulse. This system works based on the belief that your body undergoes stress and anxiety when you lie, which would result in the release of epinephrine and norepinephrine.  Polygraphs tests are not often considered a reliable source of lie detection because there are ways for people to outsmart the machine and control their nerves while lying. This would be the reasoning behind why polygraph testing is not frequently used in a court of law.


Limbic system is the center of the brain that controls anxiety and triggers the subconscious reactions that happen when someone lies

Different parts of the brain are activated when you lie, which may not be used when telling the truth

This source presents many statistics and facts, as well as explaining the gestures that our bodies due when we lie

pathologic liars have more white matter in their prefrontal lobes-could mean that this gives these people the tools to be more deceitful

moral decisions are made using the prefrontal lobe

gray matter- more awareness of morality, white matter- tool to ignore morality

rather inconclusive study but good start in the study of gray vs white matter

various facts about lying


video discussing the tell tale signs that someone is lying

what happens in the grey matter of the brain


lying stimulates 3 different sections of the brain

catecholamines are the hormones released in response to stress

catecholamines- chemical released when you lie (neurotransmitters)'s-response.html

when you are stressed, your body releases catecholamines (epinephrine, norepinephrine, dopamine)

these activate area in brain calle amygdala, which triggers emotional response

suppress activity in front of brain that control rational thought, concentration, and short term memory

catechol composition

epinephrine and norepinephrine info

adrenaline info

noradrenaline info

adrenaline info

synthetic epinephrine

norepinephrine info


methylation definition

polygraph background

composition of phenylalanine amino acid

composition of tyrosine amino acid

composition of a methyl group

About the Author
Gabi Anderson is a junior at Billings Senior High. Gabi is a dancer and a cheerleader and spends most of her time participating in these activities. She also is involved in many activities like Student Council, Senior Advocates, and Youth Leadership and maintains a 4.0 GPA. Gabi is a lover of reading and photography and enjoys spending with her friends and her dog.