AllantoinvsBakuchiol

Allantoin (5-ureidohydantoin) stimulates cell proliferation and tissue regeneration by promoting fibroblast activity, keratinocyte proliferation, and extracellular matrix synthesis including collagen and glycosaminoglycans. It acts as a mild keratolytic by promoting the natural desquamation process—loosening corneocyte adhesion and facilitating shedding—without the irritation, pH disruption, or barrier compromise associated with alpha- or beta-hydroxy acids. Allantoin has anti-inflammatory properties through modulation of prostaglandin synthesis (inhibiting COX-2 and reducing PGE2) and may downregulate pro-inflammatory cytokines. Its moisturizing effect comes from increasing the water-binding capacity of the extracellular matrix and stratum corneum; it is highly soluble and forms hydrogen bonds with water. Allantoin also promotes wound epithelialization. Its safety profile—non-irritating, non-sensitizing, non-comedogenic—makes it suitable for compromised skin, post-procedure care, and infant formulations.

Bakuchiol (meroterpene from Psoralea corylifolia) achieves retinol-like effects through RAR/RXR-independent pathways. It upregulates collagen I and III in fibroblasts via TGF-beta/Smad signaling and possibly ER-beta cross-talk. Bakuchiol downregulates MMP-1, preserving dermal collagen. It accelerates keratinocyte differentiation and stratum corneum turnover through distinct pathways. Direct antioxidant activity scavenges ROS and inhibits lipid peroxidation. Anti-inflammatory effects may involve NF-kappaB modulation. Clinical studies show comparable wrinkle reduction to 0.5% retinol; combination with retinol shows synergy. Safe during pregnancy—does not activate retinoic acid receptors.