Cuskin Vit. C+ Serum infused with Vitamin C with nanoscales lowers pigmentation and freckles while leaving the skin smooth and soft. Hyaluronic acid, which acts as a connective tissue organiser and water-holding ingredient, provides the skin with tremendous moisturising properties. Ascorbic acid (Vitamin C) is a water-soluble vitamin and naturally occurring antioxidant found in citrus fruits and leafy green vegetables.