Korff Complete Night Renew Serum 30ml: what is it? Korff Complete Night Renew Serum is an intensive treatment specifically formulated to promote nighttime skin regeneration. Mandelic Acid, with its effective brightening action, and the exclusive Chrono Age Complex, which helps regulate the circadian sleep-wake cycle, work synergistically to restore toned, smooth, and radiant skin. Signs of fatigue and aging are reduced, and the face appears radiant. Clinically proven