Phenylethylamine (PEA) is a naturally occurring trace amine found in the human body, as well as in certain foods such as chocolate. It is structurally similar to amphetamine and acts as a neuromodulator, with the ability to influence the release of neurotransmitters like dopamine and norepinephrine. The interest in PEA as a supplement to support the "dopamine system" stems from these neurochemical properties.

Scientific studies have shown that PEA can transiently increase synaptic concentrations of dopamine by inhibiting its reuptake and promoting its release, primarily in animal models and in vitro experiments. Human studies are limited, in part because PEA is rapidly metabolized by monoamine oxidase B (MAO-B), resulting in low oral bioavailability and brief physiological effects. Some research has explored the use of PEA (often in combination with MAO-B inhibitors) for mood enhancement and attention disorders, but robust clinical trials are lacking.

The overall scientific evidence directly supporting the use of PEA supplements to sustain or enhance dopamine function in humans is weak. Most claims are based on mechanistic reasoning rather than clinical outcomes. Therefore, while there is a plausible neurochemical basis for PEA's effects on dopamine, the strength of the evidence is limited, and further research is needed to substantiate its efficacy and safety in this context.