Formulated using pure vitamin C, Pure C15 is perfect for those who are experienced using vitamin C in their regime and are looking for a higher strength. KEY BENEFITS Pure vitamin C (ascorbic acid) is clinically proven to boost collagen and fight free radical damage. RESULTS This innovative serum visibly brightens skin tone, smooths fine lines, firms tired skin and refines skin texture. The result is a radiant, smooth and noticeably more youthful-looking complexion.