Objectives: In this double-blind randomized study, we evaluated the safety and efficacy of over-The-counter (OTC) bleaching products that included 2.9% hydrogen peroxide (H2O2) with two methods of application: strip and paint-on. Methods and Materials: A commonly used product was selected for each type (strip and paint-on) of OTC bleaching agent. In total, 75 volunteers were assigned randomly into five groups: Two test groups (strip and paint-on), two negative control groups (products without H2O2), and one positive control group (dentistsupervised home bleaching). The tooth shade was evaluated with a spectrophotometer and Vita shade guide at baseline and 2 weeks and 4 weeks after use. To document any adverse reactions, such as hypersensitivity or tissue irritation, all patients were examined and the Gingival Index (GI), Plaque Index (PI), and a visual analog scale (VAS) measuring the cold response were obtained. Results: There were significant differences among the five groups (p<0.001). The positive control showed the greatest color changes; then, in decreasing order, the strip-Type test group, paint-on-Type test group, and negative controls. The strip-Type bleaching agent was significantly more effective than the paint-ontype agent and the negative control, while it was significantly less effective than the dentist-supervised home bleaching. Regardless of the treatment group, the canines showed greater color changes than did the central or lateral incisors. Some cases of gingival irritation and hypersensitivity were observed, but they were mild and reversible. GI, PI, and VAS scores were not significantly changed. Conclusions: Within the limitations of this study, the results indicated that the strip-Type and paint-on-Type OTC bleaching agents were significantly less efficacious than was dentistsupervised home bleaching; however, they showed acceptable safety and efficacy. The strip-Type was more effective than was the paint-on-Type in this study.