Inclusion Criteria:

• History of clinical breast pain.
• Documentation of 6 or more sequential days of moderate or severe pain by patient daily diary.
• Conservative measures such as local heat, non-prescription analgesics, and properly fitted garments are not effective for the treatment of symptoms
• Euthyroid with no prior history of thyroid disease.
• Premenopausal female between the ages of 18 and 50.
• The presence of at least one palpable structure (nodules, cysts) and involvement (diffuse nodularity or breast thickening) of at least 25% of at least one breast surface.

Exclusion Criteria:

• History of thyroid disease
• Non-cyclic breast pain
• Treatment with gonadotropin releasing hormone (GnRH) agonist, Danocrine, tamoxifen, raloxifene, or bromocriptine within three months of starting the trial
• Initiation or change of any hormonal therapy within 6 months of enrollment; including birth control pills, hormone replacement therapy, any progestin including Norplant or Depo-Provera;
• Current treatment with iodine or iodine-containing medications or diagnostics
• Known hypersensitivity to iodine-containing products
• Breast implants;
• Oophorectomy (complete or partial)
• Uncontrolled hypertension;
• Breast biopsy breast biopsy within two months of screening; or expectation of a breast biopsy during the study for a suspicious mass present at baseline;
• Pregnant women or nursing mothers
• History of malignancy within the previous 5 years other than basal cell or squamous cell carcinoma of the skin
• History of breast cancer