Green tea (Camellia sinensis) has been investigated for its potential effects on the dopaminergic system, primarily due to its content of polyphenols (notably epigallocatechin gallate, or EGCG) and caffeine. Preclinical studies suggest that some components of green tea can modulate dopamine levels in the brain. For example, EGCG has been shown in animal models to inhibit the reuptake of dopamine, potentially increasing its availability in synaptic spaces. Caffeine, another constituent of green tea, is known to indirectly enhance dopaminergic activity by blocking adenosine receptors, which can lead to increased dopamine signaling.

However, the direct evidence in humans that green tea significantly supports or modulates dopamine levels is limited. The majority of data come from animal studies or in vitro experiments. Some human studies have observed that green tea consumption may improve mood and cognitive function, which could be partly attributed to effects on dopamine pathways, but causality and mechanisms remain unclear. Overall, while there is some scientific rationale and preliminary evidence, robust clinical evidence supporting green tea specifically for "dopamine body system" support in humans is lacking, warranting a low-to-moderate strength of evidence rating.