Recently I’ve been getting a ton of questions about desiccated thyroid from my thyroid patients and as Naturopathic Doctors have recently gained access to the prescribing of this medication, it’s a great time to do some Q&A.
So, here’s the top 5 things you need to know about Natural Desiccated Thyroid (NDT)
1. What is desiccated thyroid?
NDT is considered a more natural form of thyroid medication and is sourced from porcine (pig) thyroid glands. NDT is NOT the same as natural thyroid “extracts” (the ones found online and in health food stores – these should be avoided!). NDT is used in place of synthetic thyroid medications such as levothyroxine (T4) or cytomel (T3).
2. What is the difference between NDT and levothyroxine (Synthroid)?
Synthroid is the synthetic version of T4 which is only one of our thyroid hormones. NDT is sourced from actual thyroid glands and contains the full spectrum of thyroid hormones including T3, our most metabolically active thyroid hormone.
3. Where can I get desiccated thyroid?
NDT is available at most pharmacies by prescription only through your medical doctor or naturopathic doctor. In the US, desiccated thyroid is called armour thyroid or nature thyroid. Here in Canada, it’s referred to as desiccated thyroid, ERFA, or just plain ‘thyroid’. You don’t need to go to a compounded pharmacy to get desiccated thyroid.
4. My doctor says desiccated thyroid isn’t safe, is that true?
Historically there has been concerns about NDT doses not being standardized, meaning that in one pill you could have a different amount of hormones than the next. Because the thyroid is so sensitive to changes in hormones, this is definitely a serious concern! NDT was at one time the only medication available for hypothyroidism until the synthetic version of T4 was produced. Currently, NDT is produced by only one manufacturer in Canada (a pharmaceutical company called ERFA) and is standardized to contain specific amounts of hormone in each capsule. I don’t consider dosing standardization to be an issue in Canada using ERFA.
5. Is desiccated thyroid better than Synthroid?
This is a tough one and it really depends on the person and their current state of health. Some people do feel better on NDT due to the fact that it better represents our natural hormone production and contains T3, our most active thyroid hormone. There hasn’t been much research comparing the two, but a 2013 study compared levothyroxine to NDT and found that 49% preferred desiccated thyroid, 19% preferred levothyroxine, and 23% found no difference. So, while NDT may work well for many, it’s not for everyone.
Hope that helps!
Dr. Katie Rothwell, ND
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Hoang TD et al Desiccated thyroid extract compared with levothyroxine in the treatment of hypothyroidism: A randomized, double-blind, crossover study. J Clin Endo Metab 2013;98:1982-90. Epub March 28, 2013.