Hypothyroidism is a very common problem, especially among women. But, when it comes to treatment, there's always a debate about which thyroid medication is the best. In the conventional medical world, there is no such debate...the ONLY medication that is typically prescribed is Synthroid (usually the generic version). BUT that completely misses the boat when you look at the bigger picture (even though the scientific studies are conflicting...surprise, surprise)
Then there are the self touted 'experts' on the internet proclaiming that Synthroid is 'crap' and one of several other thyroid medications are better....
In my 25 years of clinical experience, here is the one thing I have discovered about thyroid medication...the best thyroid medication is the one that works best for the patient!
Everyone is different, and everyone has hypothyroidism for different reasons. In some cases, patients may not even NEED thyroid medication, like for instance if your hypothyroidism is actually coming from low Vitamin D...then you simply need Vitamin D!
To at least alleviate some of the confusion, I've created an overview of the types of thyroid medications and how they work. Then, you and your health care practitioner can decide which option is the best!
T4 preparations
T4 is the usual 'go to' thyroid hormone prescribed for hypothyroidism. Examples of T4 only medications are Synthroid (generic version is Levothyroxine), Levoxyl, and Tirosint.
T4 is actually a prohormone because it must convert into T3, the more active thyroid hormone, before it will work. Therein lies the major issue with T4 only preparations....There are countless things that prevent T4 from converting into T3.
Most of the conventional medical research has been done with T4 only preparations. There are a few studies which have examined the benefit of adding T3, but the results have been mixed. So, most doctors do not prescribe T3 with T4.
One important thing to note about these preparations is that the biochemical structure is quite different from human T4, and many believe this is another reason why it doesn't work as well. Also, don't forget to look at the list of fillers....
T3 Preparations
The main T3 preparation available is synthetic Liothyronine (brand equivalent is Cytomel). It comes in only 2 doses, 5 mcg and 25 mcg. It must be taken at least 2 or 3 times daily because it's effects don't last very long (peak action is usually within about 3 hours).
T3 is usually not prescribed alone but rather in combination with T4 preparations. It contains several fillers which may cause side effects, including corn and talc.
As is true for T4 preparations, brand versions typically work better than the generic versions. However, brand name thyroid medications are more expensive.
Porcine (Pig) Derived Thyroid Medications
Armour Thyroid, Nature Thyroid, NP Thyroid, and WP Thyroid are made from the thyroid glands of pigs. One reason they work better in some patients is because they contain both T3 and T4. They are touted as being 'more natural' because the biochemical structures of T3 and T4 contained in these medications is more 'biologically identical' to human T3 and T4.
There are some differences in doses and fillers in each of these preparations that also impact how well they work. For instance, Nature Thyroid contains lactose as a filler.
I typically do not use these medications in patients with autoimmune diseases (if the body is attacking it's own thyroid, it usually doesn't play well with pig thyroid).
Another thing to keep in mind is the body may develop antibodies to pork with long term use. In some cases, this explains why porcine thyroid may work well in the beginning but then stop working later.
Compounded Thyroid Preparations
Compounded thyroid medications are also more highly favored than T4 and T3 only preparations because they contain both thyroid hormones. Another appeal is doses can be individually tailored for each patient unlike all the above preparations which come in standard doses.
Compounded thyroid medications can also be prepared in sustained release capsules which improves compliance (for many people, it's hard to remember to take the T3 throughout the day).
One possible drawback to using compounded sustained release thyroid medications is that they may not work as well in patients who have gut issues. Sustained release medications rely on optimal gut health to work effectively.
So...there's the whirlwind tour of thyroid medications. Which option is best depends on numerous factors unique to each individual patient.
(P.S. Forget about discussing any of these options other than T4 with your conventional medical doctor...they usually will only prescribe T4, and maybe if you're very lucky, T3)
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