Why a Low-Iodine Diet?

Thyroid cells in your body absorb iodine, which is contained in many foods. Your doctor may ask you to avoid certain foods and medicines that contain iodine for a few weeks before your ablation procedure, Tg testing or whole body scan (WBS). Doing so will deplete your body of its natural storage of iodine, allowing any remaining thyroid cells to better absorb the radioactive iodine given to you before these procedures. Be sure to let your doctor know if you've had CAT scans, angiograms, pyelograms, stent placements or any other x-ray procedures in the month before your test since some x-ray exams use iodine-containing chemicals that could interfere with your scan.1

Low-Iodine Cooking

Being on a low iodine diet can be challenging. However, there are several cookbooks available to help you select and prepare healthy, low iodine meals before your testing if your doctor thinks this is important for your care. Visit the following links for low-iodine meal-planning suggestions:

Foods to avoid that contain iodine2,3

Foods that contain iodine to avoid | low iodine diet

Foods you can eat2,3

Foods to eat that don't contain iodine

Other tips: You may want to shop and freeze or store your ingredients before starting your diet to avoid being tempted by iodine-containing foods at the store. Note that iodine does not mean salt or sodium: non-iodized salt is fine to use on a low-iodine diet.

Thyrogen® (thyrotropin alfa for injection) 0.9 mg/mL after reconstitution


Diagnostic: Thyrogen is used to help identify thyroid disease by testing the blood for a hormone called thyroglobulin in the follow up of patients with a certain type of thyroid cancer known as well differentiated thyroid cancer. It is used with or without a radiology test using a form of iodine.

Limitations of Use:

The effect of Thyrogen on long term thyroid cancer outcomes has not been determined.

When Thyrogen is used to help detect thyroid cancer, there is still a chance all or parts of the cancer could be missed.

Ablation: Thyrogen is also used to help patients prepare for treatment with a form of iodine to remove leftover thyroid tissue in patients who have had surgery to take out the entire thyroid gland for patients with well differentiated thyroid cancer who do not have signs of thyroid cancer which has spread to other parts of the body.

Limitations of Use:

In a study of people being prepared for treatment with a form of iodine after thyroid surgery, results were similar between those who received Thyrogen and those who stopped taking their thyroid hormone. Researchers do not know if results would be similar over a longer period of time.


There have been reports of events that led to death in patients who not had surgery to have their thyroid gland removed, and in patients with thyroid cancer cells that have spread to other parts of the body.

Patients over 65 years old with large amounts of leftover thyroid tissue after surgery, or with a history of heart disease, should discuss with their physicians the risks and benefits of Thyrogen.

Thyrogen can be administered in the hospital for patients at risk for complications from Thyrogen administration.

Since Thyrogen was first approved for use, there have been reports of central nervous system problems such as stroke in young women who have a higher chance of having a stroke, and weakness on one side of the body.

Patients should remain hydrated prior to treatment with Thyrogen.

Leftover thyroid tissue after surgery and cancer cells that have spread to other parts of the body can quickly grow and become painful after Thyrogen administration.

Patients with cancer cells near their windpipe, in their central nervous system, or in their lungs may need treatment with a glucocorticoid (a medication to help prevent an increase in the size of the cancer cells before using Thyrogen.)


In clinical studies, the most common side effects reported were nausea and headache.


Pregnant patients: Thyrogen should be given to a pregnant woman only if the doctor thinks there is a clear need for it.

Breastfeeding patients: It is not known whether Thyrogen can appear in human milk. Breastfeeding women should discuss the benefits and risks of Thyrogen with their physician.

Children: Safety and effectiveness in young patients (under the age of 18) have not been established.

Elderly: Studies do not show a difference in the safety and effectiveness of Thyrogen between adult patients less than 65 years and those over 65 years of age.

Patients with kidney disease: Thyrogen exits the body much slower in dialysis patients and can lead to longer high TSH levels.

You are encouraged to report negative side effects of prescription drugs to the FDA. Visit www.fda.gov/medwatch, or call 1-800-FDA-1088.


  1. ThyCa. 2015. Treatment and follow-up papillary, follicular, variants (differentiated thyroid cancer). 2015. http://www.thyca.org/pediatric/treatment/pap/. Accessed January 2019.
  2. American Thyroid Association. Low iodine diet. 2015. http://www.thyroid.org/low-iodine-diet/. Accessed January 2019.
  3. ThyCa. Low-iodine diet Guidelines. 2015. http://thyca.org/download/document/229/Cookbook1pgEng.pdf. Accessed January 2019.