This study aimed to clinically evaluate the effectiveness of two different at-home whitening protocols and to determine which is more effective: applying the whitening gel (16% carbamide peroxide) every 24 hours (Group A) or every 48 hours (Group B) for 2 weeks. Group C received a placebo gel (glycerin) without peroxide, which was applied every 24 hours for 2 weeks. The differences in terms of tooth sensitivity were also analyzed. A sample of 60 patients was divided into three groups of 20 patients. To compare the groups, color measurements were made using a spectrophotometer, and Student t test was used for independent samples. The confidence level was set at 95% (P ≤ .05). No statistically significant differences were found between Groups A and B (P > .05). The study concluded that 16% carbamide peroxide was equally effective when applied with either protocol and obtained the same results, but the 48-hour application protocol produced less sensitivity than the 24-hour application protocol.