Cream collagen is a type of cream that contains collagen, a protein found in connective tissue, skin, tendon, bone, and cartilage. Collagen is responsible for skin elasticity and plays a role in joint and bone health. However, it is unclear whether cream collagen contains mercury or not, as this information is not provided in the search results. It is important to note that collagen supplements often contain other ingredients, such as herbs and high levels of vitamins, which could pose health risks. Therefore, it is recommended to consult with a healthcare professional before using any collagen-based products.