Dehydrated sensitive skin. Hyaluronic Acid, a powerful moisturising active ingredient, combined with high concentrations of La Roche-Posay thermal spring water, fills the skin with moisture for 24 hours. Combined with Arginine and Serine, which are excellent at trapping water for intense rehydration. Infused with water, the skin is immediately plumped up. Optimum hydration levels are restored. Hydraphase Serum is a refreshing serum to hydrate, soothe, and visibly plump skin. Fragmented Hyaluronic Acid absorbs up to 1,000 times its weight in water for immediate plumping effect and long lasting hydration Arginine and Serine, naturally present in skin, help boost hydration Antioxidant thermal spring water soothes skin Apply daily before your skincare product, avoiding the eye contour. No parabens. Intense long-lasting 24h hydration: 81% of tightness and dehydration wrinkles are smoothed away within 1 month.