I am almost done my first bottle with the Kiehl's Powerful Strength Line-Reducing Concentrate. This serum is pure 100% vitamin C. However, it has a creamy texture and upon application, you would feel a warm sensation. My dry line and expression line have definitely been less visible. I use this product every night and it has worked wonders for my skin. It does have a little bit of a funky metal smell but fades away after a few hours. I love the texture and the effectiveness.