Mavala mava-flex serum for very dry, hard and brittle nails. Mavala mava-flex serum for very dry, hard and brittle nails is a balanced concentrate based on urea, saccharides and hyaluronic acid, calcium, lemon essential oil and vitamin B5. It aims to maintain a good hydration to restore and preserve the flexibility of the plate. If you have already tried our product, please leave your opinion in the comments. Use twice a week on bare nails, ideally in the evening to allow the serum to act during the night. Apply with the brush on the entire surface of the nail previously cleansed and devoid of any trace of fat.