What are the side effects of radioactive iodine?

Permanent hypothyroidism (or underactive thyroid, when the thyroid does not produce enough hormones) is an expected side effect of RAI treatment for hyperthyroidism. Fortunately, hypothyroidism is much easier to treat than hyperthyroidism using hormone replacement therapy. This is a lifelong treatment that is safe, reliable and inexpensive.

Temporary side effects of RAI may include:

What precautions should be taken with radioactive iodine therapy?

  • Women who are pregnant or nursing should not receive RAI therapy. Pregnancy should be delayed at least six to 12 months after RAI treatment for thyroid cancer. Breast feeding should be stopped at least six weeks before RAI and should not be resumed.
  • In the days immediately following your RAI therapy, be aware of these general precautions to prevent radioactive exposure to others. Your healthcare provider will give you specific instructions on how many days to follow these precautions, which will depend on the strength of your dose of RAI.
    • Avoid prolonged, close physical contact with others, especially children and pregnant women.
    • For the first few days stay a distance of at least 6 feet away from others. Avoid public places.
    • Sleep alone in a separate bed (at least 6 feet away from another adult).
    • Do not share kitchen and cooking utensils, bedding, towels and personal items with others.
    • Do dishwashing and laundering of the items you use separately.
    • Wash your hands often and shower daily.

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