D-Aspartyl-D-Threonyl-d3-D-threonyl-d3-D-asparaginyl-D-tyrosyl-D-Threonine is a derivative of D-Threonyl-d3-D-threonyl-d3-D-asparaginyl-D-tyrosyl-D-Threonine (T405507), a labeled peptide that exhibits potent antagonism for both CCR2 and CCR5 in monocyte chemotaxis. D-Threonyl-d3-D-threonyl-d3-D-asparaginyl-D-tyrosyl-D-Threonine reduces pain in peripheral neuropathy.