Thyroid Cancer: Hormone Therapy

March 21, 2017

Thyroid Cancer: Hormone Therapy

What is hormone therapy?

Hormone therapy uses pills to give your body the hormones that were made by the thyroid gland before cancer treatment. Thyroid hormones are important because they help the body work properly.

When might hormone therapy be used for thyroid cancer?

If you’ve had surgery to remove your thyroid gland or radioactive iodine therapy, your body will no longer make the thyroid hormones it used to make. You will likely be prescribed thyroid hormone therapy to replace your lost hormones

The pituitary gland in your brain controls the thyroid. If the pituitary senses that thyroid hormone levels are low, it will make a hormone called thyroid-stimulating hormone (TSH). This hormone normally causes the thyroid gland to make as much of its hormones as the body needs. TSH is also known to promote the growth of the thyroid gland, and possibly promote the growth of thyroid cancer cells. Taking hormone therapy to keep TSH low after you have had your thyroid removed due to cancer, may help prevent some thyroid cancers from returning.

How is hormone therapy given for thyroid cancer?

Hormone therapy is usually given in the form of pills. A balanced amount of hormone pills help the body work properly and keep TSH levels low. 

The most commonly used pill is levothyroxine. It's taken at home at about the same time every day.

Blood tests will be done to watch your thyroid hormone levels and adjust the dose as needed. Different amounts are needed for each person, and the dose needed may change over time.

What are common side effects of thyroid hormone therapy?

People on thyroid hormone therapy need regular blood checks to avoid taking too little hormone, which would cause hypothyroidism. The blood checks can also help avoid taking too much hormone, which would cause hyperthyroidism.

Signs of hypothyroidism, or too little thyroid hormone, include:

  • Low energy

  • Tiredness or fatigue

  • Weight gain

  • Feeling cold all the time

  • Hair loss

  • Dry skin and hair

Signs of too much thyroid hormone, or hyperthyroidism, include:

  • Nervousness

  • Shaking

  • Weight loss without dieting

  • Trouble sleeping

  • Diarrhea

  • Cramps

  • Rapid or irregular heartbeat and chest pain

  • Excessive sweating and feeling hot

  • Over time, it may lead to thinning of the bones, called osteoporosis

Talk with your doctor about the signs you should watch for that may mean it's time to adjust your dose of hormone therapy.

Working with your healthcare provider

It's important to know which medicines you're taking. Write your medicines down, and ask your healthcare team how they work and what side effects they might have. Also be sure to talk about herbs, vitamins, and supplements you take, as some of these might cause interactions with your hormone therapy.

Talk with your healthcare providers about what signs to look for and when to call them. Make sure you know what number to call with questions. Is there a different number for evenings and weekends?

Make sure you know what dose and how to take your hormone therapy. Know where and how often you need to have blood tests done to check your thyroid hormone levels.


March 21, 2017


Sugitani, Does Postoperative Thyrotropin Suppression Therapy Truly Decrease Recurrence in Papillary Thyroid Carcinoma? The Hournal of Clinical Endocrinology and Metabolism (2010); 95(12); pp. 4576-4583

Reviewed By:  

Hurd, Robert, MD,Stump-Sutliff, Kim, RN, MSN, AOCNS