When we go through specific stages in our life, our organism synthesizes different types of chemical substances or “natural drugs”. The stage of falling in love is one of them, where large amounts of phenylethylamine are produced.

Phenylethylamine is an organic compound belonging to the group of amphetamines. In this article we will know its characteristics, its effects and what factors can trigger its synthesis.

Phenylethylamin: characteristics of this neurotransmitter

Phenylethylamine is an essential amino acid that acts as a neurotransmitter . It is an organic compound produced by the brain, belonging to the group of amphetamines. It is a natural drug manufactured by the body itself, which stimulates the nervous system.

On a chemical level, its structure is also found in complex ring systems such as Ergoline (LSD) or Morphine (morphine).

The infatuation could be due to or initiated by this molecule, phenylethylamine, which causes exaltation, joy and euphoria. Thus, it is considered the biochemical substance “responsible for love”, because when we fall in love or when we are over-excited, the body increases its production. So much so, that high amounts of phenylethylamine are found in the urine during the stage of falling in love.

This can be related to the loss of appetite, the euphoria and the capacity that a person in love has to do without sleep , as it happens in this emotional stage.

Loving disenchantment

When “our hearts are broken” or when such love is not reciprocated, after that phase of euphoria of the first stage, a period of “depression”, sadness or lethargy appears. These symptoms are very similar to those that appear in the withdrawal syndrome of a person addicted to amphetamines.

At this stage, the individual stops producing phenylethylamine naturally. As we will see later, chocolate can be a good ally at this time, since it contains phenylethylamine.

Other associated chemicals

But continuing with the stage of falling in love (or when we are emotionally matched at the love level), that is when the brain is flooded with this natural drug, phenylethylamine.

In addition, also increases levels of dopamine , an excitatory neurotransmitter responsible for feelings of pleasure, as well as levels of norepinephrine and oxytocin. In turn, dopamine influences the area of physical and mental energy (concentration and ability to recall memories).

Oxytocin is responsible for the contractions in the uterus to give birth and to make milk flow to breastfeed the baby, and it is a chemical messenger of sexual desire.

Also, phenylethylamine helps to produce other neurotransmitters , and is responsible for the fact that people in love can invest a lot of energy in thinking about the person they love, or even in having sex without feeling hungry or sleepy, even losing track of time. It is as if the body “lost” the ability to feel tired, or endure many hours more active.


In the 1980s, phenylethylamine was first studied in relation to its influence on the feeling of love. The first research was carried out at the Psychiatric Institute of New York (USA), by Dr. Donald F. Klein and Dr. Michael Lebowitz.

These researchers suggested that the brain of a lover contains large amounts of phenylethylamine . In addition, they claimed that it was responsible for changing reactions in the person’s body on a physiological level, but also on a psychological level.

Klein and Lebowitz, in their theory, also claim that the production of phenylethylamine in the brain can be triggered by an exchange of glances, a touch or a handshake . When this happens, the brain of the person in love responds with sensations and physiological changes responsible for the acts and sensations of romantic love.

These sensations or responses are the waking state, “daze”, lack of appetite and extreme happiness (or euphoria). These feelings are similar to those of using certain drugs such as cannabis, mushrooms or amphetamines.

The crush

On the other hand, infatuation itself is not eternal, and is limited in time. At the level of the organism, this is understandable, as the organism could not hold out too long with this level of activation or excitement (or if it did, it would end up being harmful). In other words, the crush can last for weeks, months or even, in some cases, a few years.

Thus, the body gradually balances out of this chemical whirlwind and a more stable stage appears, the stage of love.

What substances and situations increase their levels?

As we have seen, when there are high concentrations of phenylethylamine in the brain, B-endorphins, opioid peptides are also released which feed the secretion of neurotransmitters such as dopamine.

Phenylethylamine can be produced and activated by ingestion of certain drugs, foods or supplements . It is also triggered by certain emotions or stages (such as falling in love), or by certain physical and/or pleasant sensations that produce certain specific stimuli (for example a look).

Sport also produces the release of endorphins, as well as listening to music we like or being exposed to light.

Some of the foods that activate phenylethylamine are chocolate (carrier of phenylethylamine; produces psychoactive effects) or some types of cheese such as the so-called Stilton (a lactose variety). It consists of an English cheese, which is only produced in three English counties (Derbyshire, Leicestershine and Nottinghamshire).

Also included are bananas, eggs, raw soybeans, lentils , almonds and nuts.

Bibliographic references:

  • Freyman, R. (2011). Love, perfect future? Science Ergo Sum, 18(2), 187-191. Universidad Autónoma del Estado de México Toluca, Mexico.
  • Saiz, M. (2015). The phenylethylamine of love. Independientes, Magazine specialized in addictions.
  • Stahl, S.M. (2002). Essential Psychopharmacology. Neuroscientific bases and clinical applications. Barcelona: Ariel.