N-Acetyl-L-tryptophan-d3 is the deuterium-labeled analogue of N-Acetyl-L-tryptophan. This compound functions as an antagonist of the neurokinin receptor (NK-1R), inhibiting the binding of Substance P (SP) to NK-1R and providing neuroprotective effects that improve memory impairment and motor dysfunction. Additionally, N-Acetyl-L-tryptophan acts as an inhibitor of mitochondrial cytochrome c (Cytochrome c), offering antioxidant and anti-inflammatory benefits by reducing IL-1β expression and inhibiting caspase-1 activation. N-Acetyl-L-tryptophan shows potential for research in neurodegenerative and inflammatory disease contexts.