Homocysteic acid and the potential role of N-methyl-D-aspartate receptors in cosmetic dermatology: a review

Recent advances in neurocutaneous research have revealed that N-methyl-D-aspartate (NMDA) receptors, which are traditionally associated with neural signaling, play significant roles in skin physiology.Homocysteic acid (HCA), an endogenous NMDA receptor agonist, regulates calcium-dependent processes that influence keratinocyte differentiation, melanogenesis, and wound repair.Functional NMDA expression has been demonstrated in keratinocytes and melanocytes, suggesting a key role in epidermal homeostasis and pigmentation control.The present review summarizes emerging evidence linking HCA-mediated NMDA receptor activation to anti-aging, pigment modulation, and barrier recovery mechanisms in cosmetic dermatology.By integrating findings from molecular and cellular studies, this article highlights how NMDA receptor modulation could serve as a novel therapeutic and cosmeceutical target.Future investigations should focus on optimizing topical NMDA receptor modulators, elucidating downstream calcium signaling pathways, and validating their clinical efficacy in enhancing skin rejuvenation and pigmentation balance.