Green tea polyphenol epigallocatechin gallate (EGCG) is a strong antioxidant that has previously been 26 shown to reduce the number of plaques in HIV-infected cultured cells. Modified EGCG palmitoyl-EGCG 27 (p-EGCG), is of interest as a topical antiviral agent for herpes simplex virus (HSV-1) infections. This study 28 evaluated the effect of p-EGCG on HSV-infected Vero cells. Results of cell viability and cell proliferation 29 assays indicate that p-EGCG is not toxic to cultured Vero cells and show that modification of the green tea 30 polyphenol epigallocatechin gallate (EGCG) with palmitate increases the effectiveness of EGCG as an anti- 31 viral agent. Furthermore, p-EGCG is a more potent inhibitor of herpes simplex virus 1 (HSV-1) than EGCG 32 and can be topically applied to skin, one of the primary tissues infected by HSV. Viral binding assay, pla- 33 que forming assay, PCR, real-time PCR, and fluorescence microscopy were used to demonstrate that 34 p-EGCG concentrations of 50 lM and higher block the production of infectious HSV-1 particles. p-EGCG 35 was found to inhibit HSV-1 adsorption to Vero cells. Thus, p-EGCG may provide a novel treatment for 36 HSV-1 infections.