Bakuchiol: From structural mimicry to systems-level skin biology

Bakuchiol was initially introduced as a functional alternative to retinol based on its ability to modulate gene expression associated with skin aging. Since that initial characterization, a substantial body of evidence has emerged, supporting a broader and more integrated biological role. This narrative review critically evaluates current genomic, mechanistic and clinical data to reassess bakuchiol within dermatological science, focusing on its functional convergence with retinol and its divergence into coordinated modulation of interconnected pathways in skin biology. Gene expression and protein-level analyses demonstrate significant overlap with retinol in the regulation of extracellular matrix remodelling, epidermal differentiation and barrier function, supporting its classification as a retinol-like functional compound. However, mechanistic studies reveal distinct and complementary modes of action, including activation of Nrf2-mediated cytoprotective pathways, selective upregulation of antioxidant enzymes such as NQO1, modulation of inflammatory and melanogenic signalling networks, regulation of endocannabinoid signalling involved in epidermal homeostasis and direct engagement of mitochondrial regulatory complexes. Bakuchiol also influences retinoid transport and metabolism, including upregulation of LRAT, suggesting enhancement of endogenous retinoid activity without direct receptor activation. These effects extend to activation of conserved longevity-associated pathways, including FOXO3 signalling, supported by in vivo evidence from Caenorhabditis elegans models. Clinical studies consistently demonstrate improvements in photoaging, pigmentation and overall skin quality, with superior tolerability relative to retinol. Collectively, these findings position bakuchiol not merely as a retinol alternative, but as a systems-level bioactive that coordinates multiple regulatory networks governing skin resilience, repair and ageing.