Armour Thyroid does not contain any gluten-derived ingredients in its official formulation, but the manufacturer has not certified it as gluten-free. This distinction matters because one inactive ingredient, sodium starch glycolate, can be sourced from wheat, corn, or potato starch, and the labeling does not specify which source is used.
What’s Actually in Armour Thyroid
Armour Thyroid is a desiccated (dried) porcine thyroid hormone. Its inactive ingredients, listed on the FDA’s DailyMed database, are calcium stearate, dextrose, microcrystalline cellulose, sodium starch glycolate, and opadry white. None of these are obvious sources of gluten, and most are routinely used in medications without any wheat involvement.
The ingredient that raises questions is sodium starch glycolate. This is a common disintegrant, meaning it helps the tablet break apart in your digestive system so your body can absorb the medication. Sodium starch glycolate is typically derived from potato or corn starch, but it can also come from wheat. When derived from wheat, the processing is extensive enough that the final product generally contains very little protein, but “very little” is not the same as “none.” Neither AbbVie (the current distributor) nor the FDA label specifies the starch source for Armour Thyroid, which leaves a gap for anyone who needs a definitive answer.
Why This Matters for Thyroid Patients
The overlap between autoimmune thyroid disease and celiac disease is well documented. A meta-analysis from Columbia University’s Celiac Disease Center, pooling data from over 6,000 patients with autoimmune thyroid conditions, found that about 1 in 62 of those patients had biopsy-confirmed celiac disease. The rate was highest in children with autoimmune thyroid disease, at 6.2%, and around 1.4% in adults with hypothyroidism specifically.
If you have Hashimoto’s thyroiditis, the most common cause of hypothyroidism, your risk of also having celiac disease is meaningfully higher than the general population’s. That makes the gluten content of a daily medication a legitimate concern, not an overcautious one. Even trace amounts of gluten consumed every single day could, over time, sustain intestinal damage in someone with celiac disease.
How to Find Out the Starch Source
Your best option is to contact AbbVie’s medical information line directly and ask whether the sodium starch glycolate in Armour Thyroid is derived from wheat, corn, or potato. Pharmaceutical companies track this information through their supply chain and can typically provide an answer, though it may take a few days. Be specific when you call: ask about the starch source, not just whether the product is “gluten-free,” since the latter term can be interpreted differently depending on who answers.
You can also ask your pharmacist to contact the manufacturer on your behalf. Pharmacists have direct channels to drug manufacturers for exactly these kinds of ingredient-sourcing questions.
Thyroid Medications With Clearer Gluten-Free Status
If you need a thyroid medication with a more definitive answer, a few options stand out. Tirosint, a levothyroxine gel capsule, contains no sugars, dyes, wheat starch, lactose, or alcohol. It’s produced in a dedicated facility where no other products are made, which eliminates cross-contamination risk entirely. This makes it one of the cleanest options available for people with celiac disease or significant gluten sensitivity.
The trade-off is that Tirosint is a synthetic T4-only medication, not a desiccated thyroid product like Armour. If you specifically take Armour Thyroid because you want both T3 and T4 hormones (the reason many patients prefer it), switching to Tirosint changes your treatment approach. That’s a conversation worth having with whoever manages your thyroid care, weighing the benefits of the T3/T4 combination against the certainty of a gluten-free formulation.
Practical Steps if You’re Concerned
If you have celiac disease and currently take Armour Thyroid without symptoms, that’s a good sign but not proof the medication is safe for you long-term. Celiac-related intestinal damage can occur without noticeable symptoms, which is why blood markers for celiac antibodies are a better gauge than how you feel. If your antibody levels remain elevated despite a strict gluten-free diet, your medication is one variable worth investigating.
For people with non-celiac gluten sensitivity rather than confirmed celiac disease, the risk from trace amounts in a small tablet is likely minimal. The total weight of an Armour Thyroid tablet is small, and sodium starch glycolate makes up only a fraction of that. Even if the starch were wheat-derived, the actual gluten content per dose would be extremely low. That said, “extremely low” is a personal threshold, and your comfort level with uncertainty is yours to define.