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T3 or no T3? That is the question! Whether or not hypothyroidism patients should include T3 medications in their treatment is a debate that’s been going on for decades, with no end in sight. Ahead, a look at some of the latest thinking on whether you might need T3 as part of your treatment for an underactive thyroid gland.
When treating hypothyroidism, the goal is to find the particular dosage of the right medication that will help safely relieve symptoms and restore thyroid hormones to optimal levels. It can be somewhat complicated.
The thyroid gland produces hormones, and the two most important thyroid hormones are the storage hormone thyroxine (T4) and the active hormone triiodothyronine (T3). A healthy thyroid gland produces primarily T4; a small amount of T3 is also released. The T4 produced by the thyroid gland needs to be converted in the body into T3 before it’s usable.
When you’re hypothyroid, your thyroid isn’t producing enough T4 or T3. For healthy thyroid function and to relieve the symptoms of hypothyroidism, you need to replace this missing hormone with outside medication.
Theoretically, everyone can effectively convert T4 into T3, so the conventionally preferred treatment of hypothyroidism is levothyroxine, the synthetic form of the T4 hormone.
For the first half of the 2century, the only treatment for hypothyroidism was natural desiccated thyroid (NDT) drugs. You’ll probably recognize the name of the most prominent brand of NDT, Armour Thyroid. Other brands include NP Thyroid, Nature-Throid, and WP Thyroid. NDT contains natural forms of the two thyroid hormones, T4 and T3, and is made from the dried thyroid glands of pigs.
With the introduction of levothyroxine, namely Synthroid, in the 1950s, there was a widespread push to prescribe this synthetic T4 drug as the primary hypothyroidism treatment. Along the way, another drug was also introduced: a synthetic T3 form of thyroid hormone known as liothyronine. The brand name for this synthetic T3 is Cytomel.
Even in the 1950s, when doctors switched patients from NDT to levothyroxine, patients complained about unresolved hypothyroidism symptoms, and some of those patients asked to return to NDT. NDT has enjoyed growing market share since the 1990s when the internet empowered thyroid patients with more information about their treatment options. At the same time, integrative, holistic, and natural medicine approaches gained in popularity.
More recently, awareness of treatment options has grown. Hypothyroid patients who aren’t satisfied with the results of T4 treatment are increasingly asking their doctors to consider the addition of T3 – whether by adding liothyronine or switching to NDT.
To summarize then, at present, there are three treatment options for hypothyroidism:
- Levothyroxine (T4-only), which includes generic and brand-name levothyroxine preparations.
- Levothyroxine plus liothyronine (T4+T3)
- Natural desiccated thyroid (NDT).
(Note: A small percentage of patients with hypothyroidism take specially compounded thyroid medications that combine T4, T3, and/or NDT.)
Whether to use T3 as part of thyroid hormone replacement therapy remains controversial. On one side of the argument are the medical societies and official guidelines stating that you only need T4 for adequate replacement of thyroid hormone. On the other side are patients – and some practitioners – who argue that many patients have far better resolution of symptoms when their treatment includes T3.
More than a dozen studies comparing levothyroxine treatment – “T4-only” – to treatments with T3 have been conducted in the last two decades. Generally, they’ve found no significant differences among thyroid hormone replacement medications in terms of safety, effectiveness, or relief of hypothyroid symptoms. Some studies did, however, show that a majority of patients preferred treatment that includes T3. And several studies have shown that using NDT can result in modest weight loss not seen with T4 or T4+T3 treatments. The bottom line: Thyroid hormone replacement therapy with T4+T3 or NDT is as effective and safe as treatment with T4.
In late 2021, a team of top thyroid researchers published a study in the Journal of Clinical Endocrinology and Metabolism. The study compared the outcomes for patients taking levothyroxine (T4), levothyroxine plus liothyronine (T4+T3), and natural desiccated thyroid (NDT).
The patients were evaluated based on several factors, including their thyroid hormone levels on each treatment, self-reported symptoms of hypothyroidism, quality of life, general health, memory, and depression.
This study is groundbreaking because it was the first randomized, double-blind, crossover study to compare the three types of hypothyroidism treatment.
Some highlighted findings:
- After crossover treatment with all three therapies, NDT was the top preference for the treatment of hypothyroidism by 45% of the patients. T4+T3 was preferred by 32%, and 23% preferred levothyroxine.
- Thyroid function tests showed that the patients on T4+T3 or NDT tended to have slightly higher TSH and T3 levels and lower T4 levels than those on T4 only.
- Despite increased T3 levels in the patients on NDT or T4+T3, “there were no associated cardiovascular adverse reactions or changes in blood pressure; heart rate was only minimally accelerated by therapy with [NDT].” (The NDT patients did have a slight increase in heart rate, but it was not associated with any cardiovascular disease.) It was especially interesting to note that there was a clear difference in a subgroup of the patients on levothyroxine who were most symptomatic. Those patients had a “strong preference” for treatment containing T3 and experienced significant improvement after switching to NDT or T4/T3.
Another study, published in early 2022 in Frontiers in Endocrinology, looked at women taking T4 who still had residual symptoms. They found that even 12 weeks of treatment with added T3 improved almost improvements in almost all areas tracked. The most significant improvements were reductions in fatigue, brain fog, and cognitive problems. Overall, the quality of life was notably improved in almost all the patients studied.
Experts have shown that it’s impossible to normalize TSH, T3, and T4 levels – or the levels of T3 in tissues – on treatment with T4 only. Still, some patients do feel well on T4-only thyroid hormone replacement therapy.
If you’re taking levothyroxine and have continuing symptoms of hypothyroidism, an essential first step is to work with your practitioner to ensure you’re on a sufficient dosage of T4. Ideally, this would be a dosage that puts your TSH level in the lower end of the reference range, under 2.0.
If your TSH is optimal, but you are still experiencing symptoms, it’s time to consider T3.
As a starting point, it's recommended that you check your thyroid hormone levels -- especially your free T3 level . Even with optimal TSH, if your free T3 level is low or low-normal, you may find that you would benefit from T3 treatment.
Researchers have found that for patients on T4-only treatment, T3 thyroid levels are significantly lower than in healthy patients with the same TSH level who don’t have a diagnosed thyroid condition. A higher level of the active T3 hormone appears to reflect healthier thyroid function and may justify the addition of T3 to hypothyroidism treatment.
Remember that T4-only treatment assumes that everyone can effectively convert T4 – the inactive storage hormone – into T3, the active thyroid hormone. Research shows that this is not the case. A subset of hypothyroid patients has genetic polymorphisms, mutations that make you less capable of converting T4 into T3.
In addition, some patients have ongoing physical or life stress or nutritional deficiencies that impair the conversion of T4 into T3 and, instead, trigger conversion into Reverse T3 – an inactive form of T3 that doesn’t help relieve hypothyroidism.
Finding a doctor who understands and values T3 as a hypothyroidism treatment can become challenging. The various treatment options are considered equally safe and effective. Still, opposition to T3 continues, and it can be hard to find an open-minded practitioner. Doctors have many misconceptions about T3, making it more challenging to get a prescription for liothyronine or NDT. Specifically, many conventional doctors believe the following misinformation about T3 treatment:
- Everyone can effectively convert T4 into T3, so treatment with T3 is unnecessary. Levothyroxine treatment is all that’s needed.
- T3 is too overstimulating and can be “dangerous” because it creates excessive thyroid hormone.
- The NDT form of thyroid medication is old-fashioned, inferior to levothyroxine, and has potency and quality problems.
The key is finding a healthcare provider who acknowledges the potential benefit of treatment with T3 and knows how to prescribe it safely. Paloma’s thyroid-savvy practitioners have significant expertise in diagnosing hypothyroidism and prescribing effective treatments, including T4+T3 and NDT drugs. Paloma doctors across the nation have successfully worked with many hypothyroid patients to resolve persistent hypothyroidism symptoms using the full range of thyroid treatment options.
Because levothyroxine is considered the standard treatment, T3 drugs are frequently not covered by health insurance. If you’re not careful, adding T3 or switching to NDT could involve hefty out-of-pocket costs.
To make it affordable to add T3 into your thyroid hormone replacement therapy, here are a few tips:
Check the GoodRx prices. GoodRx surveys local pharmacies for the best prices and includes discount coupons to save you money on your medications.
- Armour: https://www.goodrx.com/armour-thyroid
- NP Thyroid: https://www.goodrx.com/np-thyroid
- Cytomel: https://www.goodrx.com/cytomel
- Liothyronine: https://www.goodrx.com/liothyronine
Consider an online discount pharmacy like Honeybee Health. You can’t use your insurance, but the cash price is often lower than the insurance copay for uncovered medications.
- Armour: https://honeybeehealth.com/drugs/armour-thyroid
- NP Thyroid: https://honeybeehealth.com/drugs/np-thyroid
- Liothyronine: https://honeybeehealth.com/drugs/details/cytomel/sigma
Check with Mark Cuban’s CostPlus Drugs, an online pharmacy. While they don’t currently have NDT, they offer excellent liothyronine prices. https://costplusdrugs.com/medications/liothyroninesodium-5mcg-tablet
Remember that healthcare professionals are extremely cautious about using T3 medications to treat hypothyroidism in pregnancy. They prefer to prescribe T4 during pregnancy because it crosses the placental barrier and helps ensure healthy fetal development.
Also, keep in mind that T3 is very short-acting and peaks quickly in the bloodstream. To mimic the thyroid’s normal production and release of T3 and avoid overstimulation or symptoms of an overactive thyroid, experts recommend splitting the daily dose of T3 and taking it two or three times a day. Be careful about the timing of your last dose of thyroid hormone medication, however. In some people, taking T3 in the late afternoon or evening can interfere with sleep.
Finally, if you’re a hypothyroid patient using a T3 drug, you should get regular blood test panels to ensure that you’re not overmedicated or undermedicated. One convenient way to get your thyroid tested is with the Paloma Complete Thyroid Blood Test kit. The affordable and convenient at-home thyroid test kit from Paloma comes with everything you need to test Thyroid Stimulating Hormone (TSH), Free Thyroxine (Free T4), Free Triiodothyronine (Free T3), and Thyroid Peroxidase Antibodies (TPO). You also have the option to add on tests for Reverse T3 (RT3) and vitamin D.