D-Arginyl-2,6-dimethyl-L-tyrosyl-L-lysyl-L-phenylalaninamide-d5 Trifluoroacetic Acid Salt is labelled D-Arginyl-2,6-dimethyl-L-tyrosyl-L-lysyl-L-phenylalaninamide (A769700) which is a mitochondrial-targeted compound that re-energizes ischemic mitochondria by interacting with cardiolipin. It is a cell-permeable antioxidant peptide.