N-Acetyl-L-tryptophan-d3 is the deuterium labeled N-Acetyl-L-tryptophan (HY-W011978). N-Acetyl-L-tryptophan is an antagonist of the neurokinin-1 receptor (NK-1R), disrupting the binding of substance P (SP) to NK-1R. This action provides neuroprotective effects, improving memory deficits and motor impairments. N-Acetyl-L-tryptophan is also an inhibitor of cytochrome c (Cytochrome c), and it exerts antioxidant and anti-inflammatory effects by inhibiting the expression of IL-1beta and the activation of caspase-1. N-Acetyl-L-tryptophan holds promise for research in neurodegenerative and inflammatory diseases[1][2][3][4].