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Are Thyroid Glandular Supplements the Same as Natural Desiccated Thyroid?

I regularly hear from thyroid patients who say that they can't get their prescription natural desiccated thyroid (NDT) medication. For many of them, it's not a cost issue -- even when paying cash, NDT is not a high-priced medication. Instead, it's because they can't find a doctor who will continue to prescribe NDT, or their doctor says they need blood tests before a refill will be ordered. Many of them have the same question: "Can I just take thyroid glandular supplements instead?"

It's a loaded question, so let's take a look.

First, what are thyroid glandular supplements? Thyroid glandulars are an over-the-counter, non-prescription supplement made from thyroid glands of animals. But here's the thing. While NDT is regulated by the FDA to include specific amounts of the T4 and T3 hormones, thyroid glandulars are technically supposed to be FREE of any thyroid hormone.

That said, studies have shown that most over-the-counter glandular thyroid supplements DO contain active thyroid hormone. One study published in the journal Thyroid actually found that nine out of ten thyroid glandulars tested contained active thyroid hormone. (It's not clear if the presence of thyroid hormone is accidental or by design.) Supplements are not well-regulated by the Food and Drug Administration, so there's simply no way to know which supplements do contain active thyroid hormone, and if so, how much they contain.

You might think that the contents need to be fully disclosed on the label, but that's not the case. If the label says "bovine thyroid tissue" or "bovine glandular tissue," however, there's a greater chance that the supplement contains active hormone. The strangest part of the whole thing is that tests found that even some plant-based thyroid supplements that include popular herbs -- like guggul or coleus forskohlii -- contained active thyroid hormone. This suggests that the hormone was specifically added to the formulation.

There's no way as a consumer for you to verify the presence of active hormone, or the amount of T4 and T3, or the source of hormone that's finding its way into the supplements. That's why glandular supplements are clearly not a substitute for prescription thyroid drugs.

Another concern is that thyroid glandular material is usually bovine, meaning that it comes from cows. (Prescription NDT is porcine, meaning that it comes from pigs.) Processing glandular products from cows introduces a small risk of exposing consumers to Creutzfeldt–Jakob disease. This rare and fatal brain condition can be contracted from contaminated meat, and is similar to the animal disease known colloquially as "mad cow disease."

My advice: If you're hypothyroid, get treated with prescription medication. You can get reputable brands of prescription NDT for as little as around $10 a month (much less than the cost of glandular supplements!)

If you are going to take a thyroid glandular supplement, only do so on the advice of your health care provider, and follow his or her recommendations regarding the brand and dosage.

If you want to take an herbal or nutritional support supplement for your thyroid -- not a "thyroid glandular" -- ask your health care provider for a recommendation. You can also consider a carefully-formulated supplement. Two that I recommend and use myself: Daily Thyroid Care, from PalomaHealth, and Thyroid Script, formulated by pharmacist and thyroid advocate Suzy Cohen Both are highly reputable sources, and you can rely on the fact that neither of these supplements contain active thyroid hormone.

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