AllantoinvsGluconolactone (PHA)

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.

Gluconolactone hydrolyzes desmosomal proteins and glycosaminoglycan bonds between corneocytes in stratum corneum, promoting desquamation. Large molecular size (178 Da vs glycolic acid 76 Da) means slow, even penetration through lipid bilayer — no irritation-causing 'hot spots' of concentrated acid. Gentle, sustained exfoliation. Six hydroxyl groups per molecule make it a potent humectant, forming hydrogen bonds with water and drawing moisture into stratum corneum. Chelates iron and copper ions, reducing metal-catalyzed free radical formation. Has antioxidant properties. Unlike AHAs, does not increase UV sensitivity. Lactone ring hydrolyzes to gluconic acid at skin pH. Ideal for sensitive skin, rosacea, those intolerant of glycolic or salicylic acid.