The MED was assessed 24h after the exposure and irradiation scheme on left side of buttock was started. The irradiation scheme con- sists of the following doses: Day 151 MED, Day 250.5 MED, Day 350.5 MED. Three test areas were involved: one was irradiation only without any product application, and the other two were applied with whitening product and vehicle (twice a day) after each UV radiation, respectively.