Avobenzone combined with various concentrations of Ethylhexyl Methoxycrylene (SolaStay® S1 quenchers) aims to see photostability studies. So that in this study tested the effect of SolaStay® S1 quenchers, SolaStay® quencher concentration, and the effect of irradiation time with sunlight on the photostability of avobenzone in commercial sunscreen formulations SPF 45. As well as determining the best SPF 45 commercial sunscreen formulations with the addition of Quenchers. The method used in this study is the spectroscopic method which uses two UV-VIS and HPLC spectrophotometer analyser. Based on the research data obtained in the presence of a quencher showed good photostability to avobenzone at certain quencher concentrations. Compared to F0, the effect of the addition of the quencher was very good, as seen from the relatively low decrease in the photodegradation rate compared to without the addition of the quencher. Viewed from the overall results, FSOL1 with the addition of 3% SolaStay® is the best SPF 45 sunscreen formulation of all formulations. This is seen from the small photodegradation results every time and the effect of skin effects was low. Keywords: Avobenzone, Quencher, Photostability, Photodegradation, SolaStay®, Sunscreen