Since I started taking EGCG I noticed coffee have zero effect on me, I can drink it like water. No heartbeat increase, no energy increase, no motivation increase, no creativity increase, no euphoric feeling, etc.. It does absolutely nothing now. Caffeine is known to increase the availability of D2/D3 receptors in some brain regions. And have indirect dopaminergic activity. EGCG seems to have some anti addiction properties, based on this study ? So is it D2 antagonist, somehow similar to how antipsychotic work ?
EGCG showed moderate inhibitory effects on the morphine-induced increase in the cAMP levels in the locus coeruleus at 100 mg/kg and the signaling of the dopamine D2 receptor at 100 microM. Effects of EGCG on the sequestration of D2 receptor were inconclusive. These results suggest that EGCG has strong pharmacological activity against the development of morphine dependence, which can be partly explained by its inhibitory effects on the morphine-induced increase in the cAMP levels in the locus coeruleus and the signaling of the dopamine D2 receptor.
The effect of epigallocatechin-3-gallate on morphine-induced memory impairments in rat: EGCG effects on morphine neurotoxicity - PubMed
Our data indicate that EGCG can improve memory in morphine-treated rats. Molecular mechanisms underlying the detected effects could be related to the prevention of apoptosis and oxidative stress in the hippocampus of morphine-treated rats.
pubmed.ncbi.nlm.nih.gov