In this study, we will recruit patients with PBC who have pruritus or fatigue despite therapy with ursodiol (the currently recommended therapy of PBC which is partially effective in relieving pruritus and fatigue). After medical evaluation and a brief period of monitoring, patients will be randomized to receive either SAMe or placebo given in oral form in similar appearing capsules twice daily. Patients will be followed at regular intervals for symptoms as monitored by validated questionnaires as well as for side effects and serum biochemical and hematological tests. After 12 weeks, therapy will be withdrawn for 2 weeks and patients will then be switched to the alternative capsules, either SAMe or placebo, for another 12 weeks. The primary endpoints of therapy will be improvements in symptoms of pruritus or fatigue or both. Secondary endpoints will be improvements in serum biochemical liver related enzymes.