Vichy volcanic mineralizing water has unique properties to strengthen the skin barrier and skin defenses against exposome aggressions.

Exposome aggressions are known to weaken certain skin functions, such as skin barrier and skin defense functions. Vichy volcanic mineralizing water (VVMW) percolates through volcanic and magmatic rocks in the Auvergne region in France to create a pure, highly mineralized water containing 15 minerals for a total mineral concentration of 5.2 g/L. Here, we provide an overview of the main results of in vitro and ex vivo studies (keratinocyte cultures, 3D reconstructed skin model, skin explants) and clinical studies to evaluate the effect of VVMW on key skin functions to help elucidate how it counteracts exposome aggressions on the skin. Properties to strengthen the skin barrier: VVMW stimulated the synthesis of tight junction proteins and keratinocyte differentiation markers in vitro. In clinical studies, VVMW accelerated cell turnover and improved skin hydration. Properties to strengthen skin antioxidant defense: VVMW stimulated the expression of antioxidant defense markers and had a higher stimulatory effect than a competitor thermal water on the expression of superoxide dismutase, catalase, and glutathione peroxidase in keratinocytes in vitro. In vivo, VVMW restored endogenous catalase activity after exposure to UVA radiation. Anti-inflammatory action: VVMW reduced substance P-induced inflammation ex vivo and lactic acid-induced stinging in vivo. Topical application of VVMW in subjects with sensitive skin showed soothing and decongestant effects by reducing skin dryness and erythema. After sodium lauryl sulfate -induced skin barrier disruption, recovery from redness and erythema was faster following application of VVMW compared to a competitor water or untreated skin. These studies illustrate that VVMW has unique properties to repair and regenerate the skin barrier, as well as to strengthen antioxidant and immune defenses, which help protect the skin against exposome aggressions.