Our integrative practitioners, Lynne Mielke, M.D. and Sandra Kreizenbeck, DNP at Optimal Health Spectrums believe that if the thyroid gland makes both, then we should replace both if it is low. It isn’t just a matter of assuming that mimicking mother nature is best (although that almost always turns out to be true), but most patients feel better on a combination of both, which is what is found in natural thyroid (Naturethroid, Armour, etc.).
We almost never prescribe just T4 alone. If someone comes in to our practice on T4 alone, we can add the T3 (Cytomel, Liothyronine), and that also works well for many. But most just change over to natural thyroid which has both hormones together in the same pill.
T3 is the active thyroid hormone. T4 is only a storage form of thyroid. Your body has to convert inactive T4 into active T3, and many people don’t convert enough. Just measuring TSH and T4 levels isn’t enough to monitor thyroid dosing properly. It is very important to measure Free T3 – the active, free fraction of T3 that actually binds to receptors and works for you. Unfortunately, some medical organizations, such as a behemoth that starts with a “K,” doesn’t even offer the Free T3 test to their patients. Remember, if you don’t test for it, you won’t find it.
There are other important things to take into account when testing thyroid levels, such as the optimal reference range. For example, optimal TSH is less than one – but the normal reference range can go up to 4.5. If your TSH is 3-4, you are still in the normal range, but it might be not be optimal for you. Remember – TSH goes down when the actual thyroid hormones (T3 and T4) go up, and TSH goes up when the thyroid hormones are down. This inverse relationship between TSH and the actual thyroid hormone levels confuses many patients.
Another critical thing to remember is the concept of peak or trough testing. The trough is when the blood level of that hormone is at its lowest, and the peak is when it is the highest. We always want to test thyroid at the trough, to make sure that it is still adequate at its lowest point. This could mean that for a part of the day it could test high at the peak, which is OK. For example, if you normally take your thyroid at 7:00 a.m., then your 24- hour trough level would be at 6:59 a.m. the next day, right before you would normally take your next dose - and that is when you should draw the blood. Then every time you test your thyroid in the future the timing needs to be the same or the test results won’t be comparing “apples to apples.” If you draw the blood before the trough, your doctor could assume that your dose is too high, and if you draw the blood beyond the trough the doctor could assume that the dose is too low – and then the doctor could make dosing decisions based on this inaccurate information. I have seen many patient’s thyroid doses get messed up this way.
Another very important thing to take into account when prescribing thyroid hormones, and one that I often see other doctors ignore - is how the patient feels. At the end of the day, if the labs are normal but you have every symptom of low thyroid – then it is probably low. It is important to rule out other causes of the symptoms of low thyroid, but many times it is helpful to do an empiric trial of higher doses of thyroid to see how the patient feels - after a full discussion of the potential risks and side-effects of taking too much thyroid hormone. I have seen many patients who finally feel normal after increasing their thyroid dose. There are several reasons why this could be, including thyroid receptor resistance. If the hormone can’t dock properly on the receptor for some reason, then the blood level could be adequate, but the thyroid function could be low, and higher doses may be necessary to overcome that receptor resistance. Unfortunately, there is no test for thyroid receptor resistance, so empiric trials of thyroid hormone are the only way to find out.
Adjusting thyroid hormone levels properly for each patient is an art, and thyroid is influenced by many other hormones as well, so balancing all hormones is essential for best results. If a patient has autoimmune thyroid antibodies (Hashimoto’s Thyroiditis) then their levels can fluctuate even more. And if Reverse T3 is high, that can block the T3 receptor and cause symptoms of low thyroid as well. However, when we take all of these issues into account, we have great results with finding the optimal thyroid level for the majority of our patients. If you feel your doctor isn’t listening to you about your thyroid symptoms, give us a call at Optimal Health Spectrums, and we will do our best to fix this for you!