Hashimoto’s Treatment: Why Do We Have Natural and Synthetic Thyroid Hormone Replacement? :: Part I

Armour Thyroid replacementWhether the cause is autoimmune – which is relatively common and is called Hashimoto’s thyroiditis – or otherwise, hypothyroidism can be treated one of two ways:  with natural hormones or synthetic hormones.

Examples of the former include supplements such as Armour, NatureThroid, and myriad others that are less well known.  Just search for “natural thyroid supplements” online and see for yourself.  Iodine, as well as selenium and other minerals, are also examples of natural remedies that help in certain situations.  The latter option involves taking synthetic (man-made) hormones such as Synthroid and several others.  Here we discuss using natural hormones to treat hypothyroidism, considering any benefits or risks.

What is the history of natural thyroid hormones, e.g. Armour, NatureThroid?

The first reported use of natural thyroid extract occurred in 1891, first in the U.K., and then in the U.S. later that same year.  It consisted (and continues to consist) of dried pig thyroid, which is first ground into a fine powder.  Then chemical binders and fillers are added to this powder, which allows it to be pressed into pill form, at which point it is ready for human consumption.

Strictly speaking, this means the pill form is not completely “natural”, but that’s mostly semantics; and these additives are required to properly form any kind of pill medication, regardless of patient philosophy.  The meat industry soon figured out that they could now sell a part of the animal that was, until then, generally leftover and useless.  Interestingly, Armour and Co. was the largest meatpacker at the time, which is why we have Armour thyroid products today.  Learn something new….

Natural hormones were first introduced commercially in 1934, as Westhroid, and were used (and continue to be used in some cases) quite successfully for years in treating hypothyroidism.  It was the only treatment available and it was incredibly effective.  Treatment was dictated by relief of symptoms, which worked in most cases, but not in a very exact way.

In the 1960s, when synthetic hormones – which would allow precision in terms of dosage – were first introduced, the use of desiccated porcine (pig) extract began to decline; by the 1980s, with the advent of better laboratory testing, a majority of patients were being prescribed synthetics.  Since then, more and more doctors have converted to levothyroxine, though some, especially older practitioners, still may use natural hormones.

More recently, researchers with the benefit of modern lab tests and equipment discovered that even mild hyperthyroidism – whether from too much medication or any other reason – has detrimental health effects.  In light of this fact, and evidence that minute differences in blood level can make a difference clinically, physicians continued to convert to the practice of prescribing synthetics, presumptively until the present proportions (which are not well known).

Why were synthetic thyroid hormones developed for thyroid patients?

Unlike with many other advances in pharmacy science over the years, it wasn’t necessarily because investigators found something better or more effective; porcine extract had been very successfully used for decades to relieve many patients of their symptoms.

Rather, it was because scientists had successfully synthesized a useful version that also relieved many patients of symptoms, but had the enormous added benefit of being conducive to precise measurement of the hormone dosage, and therefore standardization and quality assurance.

The massive reduction in uncertainty and variability regarding various products was quite important.  To be able to know exactly how much active hormone (and in what exact ratio of T4:T3) you are giving your patients, in conjunction with modern lab abilities, is immeasurably helpful to clinicians.

While I would direct you to this Armour Wikipedia link for a more complete and scientific explanation, the basic reasons were pretty simple: doctors were able to offer their patients treatment that was as good if not better than natural thyroid extract, in a very controlled and standardized dose, rather than rely on absence of symptoms as an indicator of successful treatment.

While the latter system clearly works, it is by its very nature, far less accurate and precise – in an arena where really tiny differences can be quite significant.  There did appear to be some interest in attempting to standardize and regulate desiccated thyroid extract decades ago, but the results are not clear, and not much more was found on the topic.

In a related matter, the above reasons and their consequences also promoted an environment where these medications could be tightly regulated and restricted, in terms of contents, additives allowed, amount of active ingredients per pill, etc.  Regardless of your feelings about big pharma and government – justified as they may be – regulation is an extremely important part of the process that brings medication from those companies, through that bureaucracy, and safely to you.

Again, there are other more technical reasons and explanations that are outside the scope of this article, but are easily found online.

Coming next week – part 2 of Natural Thyroid Supplements, answering the questions about the studies done about safety and efficacy of desiccated thyroid replacement and a review of the controversy surrounding its prescription.


About the Author
Dr. Rothbard is a professional medical writer and consultant based in New York City, specializing in medical education articles targeted at a variety of audiences, from children through clinicians.  After leaving medicine, he worked as a biology and medical science educator for several years, before deciding to pursue writing full-time.  He may be reached at [email protected].

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