OBJECTIVE: To evaluate the bleaching efficacy and hydrogen peroxide (HP) permeability of whitening pens, with and without light-activation systems. Also, pulp temperature and physicochemical properties were assessed, as well as the characterization of the light sources. MATERIAL AND METHODS: Ninety premolars were distributed into nine groups (n=10): untreated, Colgate Optic White Pen ComfortFit LED (CF), Colgate Optic White Pen Express (CX), Equate Teeth Whitening Kit (EW) and Zimba Teeth Whitening Kit (ZW), with and without light-activation. Bleaching efficacy (WI RESULTS: ZW light device exhibited the highest power and irradiance (p<
0.05). EW and ZW emitted blue light (peak:456 nm), while CF device emitted violet light (peak:405 nm). Light-activation did not significantly impact WI CONCLUSIONS: Light-activation had no significant impact on bleaching efficacy (WI CLINICAL SIGNIFICANCE: It is not essential to combine light devices with whitening pens to achieve bleaching efficacy.