My daughter (11 mos) has been on .01 Florinef (.005 twice daily) since she was born. My ped endos have told me that this is dose does not change with body mass, and that we can expect this to be her Florinef dose even as an adult. In contrast, we continually fine tune her Cortef dose to get as close as possible to 15 mg/m2 as possible. She is generally well controlled.