Clinically proven to brighten skin and visibly improve wrinkles in 7 days[1] and 100% skin barrier friendly[1], C-Tetra Advanced is designed to deliver high-impact visible radiance, smooth skin, and protect daily with antioxidants. This intelligent ingredient complex combines a potent 20% stabilized vitamin C with restorative phytoexosomes for deep, controlled release, and acetylzingerone, an omni-antioxidant, to neutralize the aging effects of free radicals. The result? A high-performance anti-aging vitamin C serum that works smarter, not harder. Apply as part of your morning skincare routine. Massage 2-3 times onto your face, neck, and décolletage. Follow with a moisturizer and always finish with sunscreen.