The Obagi-C RX Regimen Kit is a great system because it is a Vitamin C system that combines a patented formula that consists of 4% prescription strength Hydroquinone and Vitamin C, which come together to give the consumer an excellent penetration to all levels of the skin, which results in what Obagi calls Photolumines Skin. When you use the Obagi RX C Regimen Kit you will find that your skin is more radiant and luminescent than it would be if you were not using the products or using something else. All of the products help to heal the skin and keep it in perfect condition every day. The Obagi-C RX Regimen Kit is a great buy for anyone who wants more radiant skin on their face and neck.