Purity >95%. As a well-known FPR antagonist;formyl peptide receptor antagonist Boc-Phe-Leu-Phe-Leu-Phe is used extensively in FPR research. In regard to neutrophils;it was found that treatment of mice with Boc-PLPLP results in 40% reduction in neutrophil counts recovered in bronchoalveolar lavage fluid;compared with infected mice receiving placebo.