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Is your thyroid medication gluten-free?

Medically reviewed by Sally Chao, MD. Last updated on Sep 21, 2023.

Official answer


According to the U.S. Food and Drug Administration (FDA), most drugs do not contain gluten, so it is unlikely that your thyroid medicine has gluten in it. To be sure, ask your pharmacist to verify that the product you are prescribed does not contain any gluten.

Thyroid hormone replacement medications are produced by different drug manufacturers and approved by the FDA.

A 2004 U.S. law requires that a food product containing any one of eight common food allergens, including gluten, must have the allergen clearly listed on the label. However, this law does not apply to drug products. The FDA does encourage drug manufacturers to include information regarding gluten content in drug product information, but it does not require it. Therefore, gluten content may or may not be stated specifically.

However, drug manufacturers are required to list a drug's active and inactive ingredients in the product information. The ingredients to look for in the drug product information is the presence of wheat flour or wheat gluten. If these are not listed, then the product is unlikely to contain even trace amounts of gluten and would be safe for a person with gluten intolerance.

Thyroid hormone medications are used to treat hypothyroidism, which is when your own thyroid gland does not produce enough thyroid hormone. Thyroid hormones help your body regulate important bodily functions, such as body temperature and metabolism.

Some thyroid replacement medications available include:

Some of the drug labels in this class of medications include a clear gluten statement, and some do not.

If you are unsure if your thyroid medicine contains any gluten, ask your pharmacist to check the drug product information or contact the drug manufacturer to verify it is gluten-free. Once you have established that your medicine is free of gluten, request that your doctor and pharmacist do not change it to a different manufacturer for future prescriptions. If it is necessary to change to a different product, then the gluten content will need to be verified again.

Always tell any health care provider, especially anyone prescribing a medicine for you, as well as the pharmacist dispensing the medicine, about any food or medication allergies you have, including the symptoms you experience. This will enable them to discuss the potential risks and benefits of a medicine for you.

If you develop any type of unexpected adverse reaction to a medicine, consider reporting the event to the FDA using the MedWatch reporting system.

Gluten is a protein found in wheat, barley and rye. Some individuals have an intolerance to gluten or a disease called celiac disease. These individuals may experience:

  • Severe diarrhea
  • Abdominal cramping
  • Weight loss
  • A rash when gluten is eaten

The treatment is to avoid eating gluten.

  1. U.S. Food and Drug Administration (FDA). Medications and gluten. Available at: [Accessed August 30, 2021].
  2. American Association of Clinical Endocrinology (AACE). Thyroid. Available at: [Accessed September 3, 2021].
  3. American College of Allergy, Asthma, and Immunology (ACAAI). Wheat allergy and gluten intolerance. Available at: [Accessed September 3, 2021].
  4. Celiac Foundation. Gluten in medicines, vitamins, and supplements. Available at: [Accessed September 3, 2021].
  5. U.S. Food and Drug Administration (FDA). MedWatch. Available at: [Accessed September 8, 2021].

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