Did you know that you can actually take thyroid medication in the afternoon? Surprised? I didn’t know this to be true or a common medical practice option either.
You may have heard of the viral phrase: “I was this many years when I found out (insert common knowledge item here)…”. Well, that applied to me, a 32 year old physician assistant practitioner with approximately eight years of medical experience. I had NO idea that thyroid medication could be dosed twice daily (once in the morning and once in the afternoon) with advantageous health benefits.
Most traditionally, a thyroid bottle prescription will come with label instructions telling the patient to: “Take one pill in the early morning, thirty minutes away from food and other medications”. So, why would clients alternatively ingest thyroid medication twice a day, which in the medical world we refer to as “BID dosing”? What benefits align to using it in such a way? And can all thyroid medications utilize BID dosing? Let’s dive into the stickiness of this situation and I’ll explain.
Levothyroxine or Synthroid, a synthetic thyroid hormone formulation, contains a lab-derived thyroid hormone called T4. T4 is what your thyroid gland predominantly produces throughout the day. The average 150 pound male/female makes about 90 micrograms of T4 over a 24 hour period routinely.
Additionally, the average 150 pound male/female also produces five micrograms of T3 daily, from your thyroid gland. T4 is the “inactive” form of your thyroid hormone whereas T3 is the “active” form of thyroid hormone, which manifests all the benefits of your thyroid’s functionality. For instance, commonly known thyroid functions include: sustaining strong hair, skin and nails, regulating smooth & daily bowel movements, supporting cardiac function, controlling your thermogenics (maintaining a correct core body temperature), assisting with mental clarity, alleviating muscle aches & joint pains… and more.
Presuming your body has no genetic deficiencies, no toxic environmental pollutants and a functioning organ system – the average human being will convert its “extended release” T4 supply into active T3 throughout the day. One example of this occurs when you exercise. Recognizing the increased demand of your skeletal muscle cells, your body will demand more energy be delivered into your peripheral tissues. Thus, to do so, your muscle cells will uptake some of your T4 and use enzymes, called deiodinase, to convert T4 into active T3. On average, a standard 150 pound male/female converts approximately 25 micrograms daily of T4 into T3.
It is also important to know that T4, once produced, will circulate in the body (has a shelf life) for about two weeks. That’s a long time! T3, by comparison, has a shorter life span and nearly half of its quantity is used and degraded in approximately six to eight hours. That’s a whole lot faster than two weeks!
Now that we have a better understanding of basic, background thyroid hormone mechanics, let’s circle back to the principles of thyroid replacement hormone therapy dosing.
Imagine a client comes into the office describing, “Hey, I had a thyroidectomy and now, I feel sluggish, my hair is falling out, my muscles ache, I can’t think clearly, and I’m gaining a ton of weight. How can you help me?”.
The standard of care from a traditional medical model would be to offer and place this post-thyroidectomy patient on thyroid replacement hormone therapy using Levothyroxine or Synthroid, lab-derived T4 thyroid hormone. Thus, when selecting this medication, clinicians are presuming that this post-thyroidectomy client can functionally and appropriately convert T4 into T3 throughout the duration of the medications’ shelf life. Spoiler alert: not all clients can. Also recall, the average 150lb person is used to producing a small quantity, 5mcg daily, of T3. However, a total thyroidectomy client will no longer be capable of such since their thyroid organ cells have been removed.
So, is standard synthetic T4 hormone replacement therapy for a post-thyroidectomy client always enough? Stay tuned for part II – dropping next week, where will discuss differing therapeutic options (and opinions) for this client scenario.