Bio-based succinic acid (bSU) has emerged as a promising mild exfoliating agent, yet its effects on desquamation pathways, barrier-related protein regulation, and irritation potential remain insufficiently characterized in human-relevant skin models. Therefore, this study systematically evaluated bSU against salicylic acid (SA) using reconstructed human epidermis and human skin explants to assess irritation profile and desquamation-related biological responses. Our findings reveal that bSU facilitates controlled corneocyte shedding by modulating the targets LEKTI, KLK, and CDSN. Moreover, bSU demonstrated a favorable ability to maintain physiological skin surface acidity, all while minimizing inflammatory activation. These results position bSU as a balanced exfoliating bioactive that effectively promotes stratum corneum renewal while preserving cutaneous barrier homeostasis, providing mechanistic insights to support its development in advanced mild exfoliation formulations.