Visibly reduces the appearance of Cellulite. Nivea Body Good-bye Cellulite Gel-Cream visibly reduces the appearance of cellulite. How does it work? L-Carnitine is a substance which is naturally present in the skin. It is known to be involved in the fat metabolism more specifically it supports the conversion of fat components into energy. A sufficient amount of L-Carnitine in the skin is therefore beneficial. What does it mean for your skin? Noticeably firmer skin within 2 weeks. Visible reduction in the appearance of cellulite within 4 weeks.