Serum nails MAVALA MAVA-FLEX. Nail serum very dry, too hard and brittle that often absorbing strips are exposed to external factors such as chemicals, water, the sun, or internal, such as age, diet or hereditary tendency. It is made with a concentrated urea, calcium, essential oil of lemon and vitamin B5, which penetrates the nail to hydrate and strengthen it. The result is healthy, flexible, bright and soft nails that will stop breaking.