2-MNG 2-mercaptonicotinoyl glycine 4-n-BR 4-n-butyl-resorcinol DT delayed tanning IPD immediate pigment darkening ITA individual typology angles LHA lipohydroxy acid MED minimal erythemal dose MSX Mexoryl-SX PPD persistent pigment darkening UVA ultraviolet A UVB ultraviolet B UVDL UV daylight UVR ultraviolet rays 1 INTRODUCTION Ultraviolet rays (UVR) impact skin pigmentation via two successive reactions with distinct mechanisms.1 First, photooxidation and redistribution of preexisting melanin...