Neurochemicals regulate countless physiological processes and influence basic functions. Among these are trace amines, which exist at very low concentrations but exert significant effects on the central nervous system. These compounds, including substances like tyramine and tryptamine, modulate major neurotransmitter systems. This article explores Phenethylamine (PEA), a powerful, naturally occurring trace amine and neurochemical.
Defining Phenethylamine (PEA)
Phenethylamine is an organic compound that the human body naturally produces and is classified as an endogenous neuroactive trace amine. The “trace” designation indicates that its concentration in the brain is hundreds of times lower than that of classical neurotransmitters like dopamine or serotonin. Despite its low levels, PEA is synthesized in the central nervous system at a rate comparable to the synthesis of dopamine.
The compound’s structure is a simple two-carbon chain attached to a benzene ring and an amine group. This architecture makes it the parent compound for a large class of substances known as phenethylamines, which includes compounds like amphetamine. PEA is created internally through the decarboxylation of the amino acid L-phenylalanine, a process catalyzed by the enzyme aromatic L-amino acid decarboxylase. This allows PEA to act as a native stimulant within the brain and spinal cord.
Natural Sources and Intake
Phenethylamine is not only produced within the body but is also found in various external sources. Certain fermented foods, such as chocolate, contain PEA, with levels increasing during the fermentation and roasting of cocoa beans. Specific cheeses and other microbial products also contain this trace amine.
When PEA is consumed orally, its presence in the body is often short-lived. The enzyme Monoamine Oxidase B (MAO-B) is abundant in the gut and liver, where it rapidly metabolizes the ingested compound into phenylacetic acid. This rapid breakdown severely limits the amount of PEA that can cross the blood-brain barrier and reach the central nervous system. Consuming PEA-rich foods or a supplement alone may not lead to significant systemic effects unless an MAO-B inhibitor is also present.
PEA’s Role in Brain Chemistry
In the brain, PEA functions primarily as a neuromodulator, fine-tuning the activity of major monoamine neurotransmitter systems. Its mechanism of action involves interacting with a specialized family of proteins called trace amine-associated receptors (TAARs), particularly TAAR1. PEA is a potent agonist of TAAR1, and this binding is thought to mediate many of its neurochemical effects.
PEA also acts as a norepinephrine-dopamine releasing agent. It achieves this by entering neurons via the dopamine transporter (DAT) and causing the transporter to operate in reverse. This action leads to a rapid, non-vesicular release of dopamine and norepinephrine from the nerve terminal into the synaptic cleft. The increase in these neurotransmitters contributes to a short-term elevation in energy, focus, and enhanced well-being. The effects of PEA are transient, lasting only a few minutes, which is consistent with its rapid metabolic turnover in the brain.