Overview Early Levothyroxine Post Radioactive Iodine Status: Completed Trial end date: 2017-04-01 Target enrollment: Participant gender: Summary The study will try to answer the question of whether early treatment with levothyroxine at 4 weeks after radioactive iodine for Graves'disease will prevent overt hypothyroidism (low thyroid hormone levels). Phase: Phase 2/Phase 3 Details Lead Sponsor: Mayo ClinicTreatments: HormonesIodine