In the realm of skincare, a question often arises: should I use niacinamide or salicylic acid first when layering my products for optimal efficacy? This inquiry, while seemingly straightforward, delves into the intricacies of how these two potent ingredients interact within the skin’s ecosystem. Given their unique properties—niacinamide being celebrated for its multifunctional benefits, including reducing inflammation and improving skin barrier function, while salicylic acid is renowned for its exfoliating prowess and ability to penetrate pores—how does one determine the appropriate sequence for application? Might the order in which they are applied influence their absorption rates and overall effectiveness? Could utilizing one before the other create potential conflicts, or is there a harmonious synergy to be discovered? Furthermore, how do individual skin types and concerns, such as acne-prone or sensitive skin, play a role in this decision-making process? Is there a universally accepted approach, or does it require a degree of experimentation to ascertain what yields the best results?