Mycophenolate mofetil (MMF), the ester prodrug of mycophenolic acid (MPA), is a potent immunosuppressive agent that is used as a part of standard immunosuppressive regimens. MMF is usually administered at a fixed oral dosage, and therapeutic drug monitoring is not routinely performed. Recent evidence, however, suggests that pharmacokinetic monitoring could be advisable. MMF administration may be sometimes associated with tolerability problems, as a result of gastrointestinal adverse events, such as nausea/vomiting, diarrhea, abdominal pain, and gastritis. For overcoming these problems, an enteric-coated formulation of mycophenolate sodium (EC-MPS) has been developed. Via its advanced formulation, EC-MPS has the potential to extend the therapeutic window of MPA through enhanced tolerability relative to MMF, because it releases MPA in the small intestine instead of the stomach.