When contemplating the optimal regimen for skincare, a prevalent inquiry arises: Should one utilize a Vitamin C serum during the nighttime hours? Is it perhaps more beneficial to incorporate this potent antioxidant into the evening routine rather than the morning? Given that Vitamin C is renowned for its ability to brighten the complexion and combat the effects of oxidative stress, what implications might its application at night have on its efficacy? Could it be that the skin’s natural repair cycle, which predominantly occurs while we sleep, enhances the absorption and effectiveness of such a serum? Furthermore, would there be potential interactions with other products commonly used at night, such as retinoids or heavy moisturizers? How significant is the role of circadian rhythms in the skin’s response to topical treatments? Are there unique skin types that would particularly benefit from nighttime use of Vitamin C? Such considerations warrant thorough examination.