Selenium and Myo-Inositol Supplements for Hashimoto’s

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Millions of Americans are battling Hashimoto’s thyroiditis. In this autoimmune condition, your body turns against its thyroid, hijacking energy and metabolism and causing fatigue, weight gain, and other debilitating symptoms. What if the standard treatment – thyroid hormone replacement medication – isn’t enough? 

Researchers have just dropped a bombshell: The combination of selenium and myo-inositol supplements could be a missing link for taming thyroid autoimmunity and optimizing thyroid health. This dynamic duo is shaking up treatment plans—with studies showing it could combat inflammation, reduce thyroid antibodies, and help thyroid medication work smarter and faster to resolve hypothyroidism. Learn more about how combining selenium with myo-inositol is a potential game-changer for Hashimoto’s patients struggling to maintain optimal thyroid function.  

Selenium is an essential trace mineral that is crucial to human health. It is a component of selenoproteins necessary for DNA synthesis, thyroid hormone metabolism, and protection against oxidative damage and infections. Selenium is naturally found in various foods, including Brazil nuts, seafood, meats, and cereals. However, the selenium concentration in food depends on the soil and water content where the food was grown.

Selenium is a critical micronutrient for thyroid health, playing a dual role in hormone production and antioxidant defense. The thyroid gland contains the highest concentration of selenium in the body, where it integrates into selenoproteins like glutathione peroxidase and iodothyronine deiodinases. These enzymes are essential for converting thyroxine (T4) into its active form, triiodothyronine (T3). Selenium also neutralizes reactive oxygen species generated during thyroid hormone synthesis, protecting glandular tissues from oxidative damage. Without adequate selenium, the thyroid struggles to maintain hormone balance and becomes vulnerable to inflammation and dysfunction.

The thyroid’s reliance on selenium stems from its unique metabolic demands. Selenoproteins like glutathione peroxidase break down excess hydrogen peroxide in the body and help prevent oxidative stress that could trigger autoimmune responses. This protective mechanism is vital in Hashimoto’s thyroiditis. Studies link selenium deficiency to elevated thyroid peroxidase antibodies (TPOAb), enlarged thyroid volume, and increased risk of autoimmune thyroid disorders.

For people with Hashimoto’s, selenium supplementation shows measurable benefits. A 2024 meta-analysis of 35 randomized trials found that selenium reduced thyroid-stimulating hormone (TSH) levels in patients not yet on thyroid hormone replacement. Multiple studies demonstrate that 100 to 200 µg/day of selenomethionine – the organic form with superior bioavailability – lowers TPOAb titers by up to 40%, particularly in those with baseline levels exceeding 1,200 IU/mL. This immune-modulating effect correlates with slowed disease progression. Some research also notes enhanced patient-reported well-being, though these findings are less consistent.

While promising, selenium’s therapeutic use requires nuance. Benefits appear dose- and form-dependent, with selenomethionine outperforming inorganic sodium selenite. Excess selenium intake – at more than 400 µg/day --  can impair thyroid function, emphasizing the need for individualized dosing. For now, maintaining “selenostasis” through diet or targeted supplementation remains a key strategy in managing Hashimoto ’s-associated thyroid dysfunction.

Paloma Health’s Selenium Guide, available for free download, has more information about the benefits of selenium for thyroid health. 

Myo-inositol is a naturally occurring carbohydrate that belongs to the B-vitamin complex family, although it is technically a form of sugar alcohol. It is naturally found in various foods such as fruits, beans, grains, and especially nuts, with an average intake of about 720 mg in a typical 2000-calorie American diet. Myo-inositol plays a crucial role in several cellular processes, acting as a messenger for cells and helping with functions like insulin regulation and neurotransmitter binding. It is essential for insulin signaling, glucose metabolism, mood regulation, and other critical bodily processes.

The human body can produce about 4 g/day of myo-inositol endogenously, primarily in the kidneys, to supplement the dietary intake. This nutrient has gained attention for its potential health benefits, including improving metabolic syndrome, reducing the risk of gestational diabetes, and aiding in weight management, particularly for individuals with conditions like polycystic ovary syndrome (PCOS)

Myo-inositol plays a vital role in thyroid physiology and has emerged as a promising therapeutic agent for managing Hashimoto’s thyroiditis. The thyroid gland requires myo-inositol to regulate iodine and thyroid hormone biosynthesis, processes that are essential for producing T4 and T3 thyroid hormones. Myo-inositol also helps the thyroid gland to maintain euthyroid or “normal” status even under stress. Without adequate myo-inositol, TSH resistance can develop, leading to elevated TSH levels and impaired hormone production.

Myo-inositol supplementation has multifaceted benefits for people with Hashimoto’s. Clinical studies highlight its ability to reduce TSH levels by improving TSH receptor sensitivity, effectively “lowering the volume” of TSH signaling required for thyroid activation. 

For people with Hashimoto’s, myo-inositol supplementation offers a proactive approach to managing both hormonal and immune dysfunction. Studies recommend doses of 600 mg/day, with a commitment to taking it for 6 to 12 months. By enhancing TSH sensitivity, reducing autoantibodies, and supporting hormone synthesis, myo-inositol acts as a valuable complement to conventional therapies. 

For more information on myo-inositol, read Can Myo-Inositol Improve Hashimoto’s Thyroiditis at the Paloma Health blog.

As you can see, we already have evidence that selenium and myo-inositol each have significant benefits for people with Hashimoto’s and hypothyroidism. Now, new research shows that taking both has synergistic properties, significantly increasing their effectiveness and benefits. 

A study published in late 2024 reported on a 6-month trial involving myo-inositol and selenium supplementation. The study looked at two groups of patients. One group took selenium alone -- 83-166 μg daily; the other group took selenium plus 600 mg daily of myo-inositol. 

The results offered surprisingly good news for Hashimoto’s patients. The combination of supplements: 

• Helped individuals stabilize their TSH levels 42% faster than selenium alone, reducing the time needed to find optimal medication dosages.  
• Reduced TSH levels by 31% to 38%. The reduction resulting from the supplement combination is 115% greater than taking selenium alone. 
• Significantly decreased anti-thyroid peroxidase (TPOAb) and anti-thyroglobulin (TgAb) antibodies, markers of autoimmune activity. Specifically, TgAb levels were reduced by 51% when taking the combination, compared to selenium alone. 
• Free T4 levels were increased.
• Thyroid function was improved.
• Compared to selenium alone, patients reported faster relief and symptom resolution when taking the combination. 

Let’s take a more in-depth look at the benefits of combining these two supplements.  

Thyroid function improvement

The combination of selenium and myo-inositol supplementation positively affects thyroid function. In patients with Hashimoto’s thyroiditis, particularly those with subclinical hypothyroidism, the combination has been shown to reduce thyroid-stimulating hormone (TSH) levels significantly. Even going back to a 2013 study, it was demonstrated that patients treated with both selenium and myo-inositol experienced a reduction in TSH levels of up to one-third, while those treated with selenium alone showed no change in TSH.

The improvement in thyroid function is not limited to TSH levels. Research has also indicated that this combination can help restore euthyroidism, the medical term for normal thyroid function, in patients with subclinical hypothyroidism. This is particularly important as it can help prevent the progression to overt hypothyroidism, a more severe form of thyroid dysfunction.

Reduction in thyroid antibodies

Hashimoto’s thyroiditis is characterized by the presence of thyroid autoantibodies, primarily thyroid peroxidase antibodies (TPOAb) and thyroglobulin antibodies (TgAb). The combination of selenium and myo-inositol has effectively reduced these antibody levels, compared to less reduction with selenium alone.

Synergistic effects

The synergistic action of selenium and myo-inositol is a key factor in their effectiveness. While selenium has long been recognized for its benefits in Hashimoto’s thyroiditis, adding myo-inositol amplifies these effects.

Symptom improvement and quality of life

Beyond the measurable changes in thyroid function and antibody levels, patients supplementing with selenium and myo-inositol often report improvements in their overall well-being and quality of life. This includes a reduction in thyroid-related symptoms and an enhancement in personal well-being assessments.

The combination has been associated with improvements in various symptoms commonly experienced by those with Hashimoto’s, such as fatigue, weight gain, and mood disturbances. By addressing these symptoms, the combination of supplements can significantly impact patients’ daily lives and overall health.

This combination is particularly effective in patients who have Hashimoto’s thyroiditis with otherwise normal thyroid levels or who are subclinically hypothyroid.

Potential for remission

Some studies have suggested that the combination of selenium and myo-inositol may lead to remission in some cases of Hashimoto’s thyroiditis. While more research is needed to understand the long-term effects and potential for remission fully, these initial findings are encouraging for patients seeking to manage their condition effectively.

Anti-inflammatory and antioxidant effects

Both selenium and myo-inositol possess anti-inflammatory and antioxidant properties, which are beneficial in managing Hashimoto’s thyroiditis. Inflammation and oxidative stress play significant roles in the progression of autoimmune thyroid diseases. The supplement combination may help slow disease progression and protect thyroid tissue from further damage by combating these factors.

Hormonal balance and metabolic health

The benefits of selenium and myo-inositol extend beyond thyroid health. This combination has shown positive effects on overall hormonal balance and metabolic health, which are often disrupted in individuals with Hashimoto’s thyroiditis.

Myo-inositol, in particular, has been noted for its ability to improve insulin sensitivity and regulate blood sugar levels. This is especially relevant for Hashimoto’s patients, as there is a known connection between thyroid dysfunction and metabolic disorders like insulin resistance and polycystic ovary syndrome (PCOS).

Safety and tolerability

One of the advantages of selenium and myo-inositol supplementation is its generally good safety profile. Studies have reported no significant side effects from this combination when used at recommended doses. This makes it an attractive option for long-term management of Hashimoto’s thyroiditis, especially for patients who may be seeking alternatives or adjuncts to traditional thyroid hormone replacement therapy.

Potential for reducing medication dependence

While more research is needed in this area, some studies suggest that supplementing with selenium and myo-inositol may help reduce the need for thyroid hormone medication. This potential to delay the need for medication in people with borderline hypothyroidism could be particularly beneficial for patients in the early stages of Hashimoto’s thyroiditis.

Supplementing with selenium and myo-inositol can be a practical and effective approach for supporting thyroid health, particularly for individuals with subclinical hypothyroidism or autoimmune Hashimoto’s thyroiditis. 

For patients considering supplementation, it’s crucial to understand that dosage and duration play significant roles in achieving optimal results. Clinical studies have consistently used a combination of 83-166 μg of selenium (typically in the form of selenomethionine) and 600 mg of myo-inositol daily. This specific dosage has demonstrated efficacy in improving thyroid function and reducing antibody levels.

The duration of supplementation is equally important. While some improvements may be observed after 3 months, research indicates that a minimum of 6 months of consistent supplementation is necessary to achieve the most significant benefits. This extended period allows for the gradual restoration of thyroid function and reduction of autoimmune markers. Some studies even suggest that continuing the supplementation for up to a year may provide additional benefits.

It’s worth noting that the timing of supplement intake can also influence its effectiveness. For optimal absorption, it’s recommended to take the supplement either 30 minutes before or 2 hours after meals. Additionally, if you’re taking thyroid medication, it’s crucial to separate the intake of selenium and myo-inositol supplements by at least 30 to 60 minutes to avoid potential interactions.

While supplementation can be beneficial, it’s essential to approach it under the guidance of a healthcare professional. Regular monitoring of thyroid function through blood tests (every 3 months at minimum) is recommended to assess the supplement’s effectiveness and determine if any adjustments to thyroid medication are necessary. This personalized approach ensures that the supplementation regimen is tailored to individual needs and provides the most significant benefits for thyroid health.

Note: Don’t exceed 400 μg/day of selenium from all sources – including multivitamins, supplements, and foods. Consistently taking more than the maximum recommended amount of selenium intake can be toxic. 

While the latest research focuses on selenium and myo-inositol supplementation, Hashimoto’s patients should also support thyroid and immune health with some additional approaches.  

Manage stress 

It’s important to build regular stress management into your health routine. Chronic stress significantly impacts autoimmune conditions through multiple physiological pathways. Prolonged stress elevates cortisol levels, which disrupts immune system balance by suppressing protective regulatory T-cells while stimulating pro-inflammatory cytokines. This hormonal imbalance creates an environment conducive to autoimmune flare-ups. Simultaneously, stress-induced digestive dysfunction impairs selenium absorption – a critical mineral for thyroid health and antioxidant defenses. Compounding these effects, chronic stress interferes with converting inactive T4 thyroid hormone to active T3. This metabolic disruption can worsen hypothyroid symptoms even in medicated patients. 

Optimize gut health  

Emerging research reveals profound connections between gut microbiome composition and autoimmune thyroid function. A balanced intestinal ecosystem helps regulate immune responses by maintaining gut barrier integrity and producing short-chain fatty acids that modulate inflammation. Specific probiotic strains like Lactobacillus reuteri demonstrate potential for reducing thyroid peroxidase antibody levels. The gut-thyroid axis also significantly influences nutrient absorption, particularly of selenium, zinc, and iron – all essential for thyroid hormone synthesis. Dysbiosis-driven intestinal permeability (“leaky gut”) allows undigested food particles and endotoxins to enter circulation, triggering systemic inflammation that may exacerbate autoimmune activity.

Monitor your vitamin D levels

Vitamin D status plays a crucial role in autoimmune thyroid management, with studies showing that serum levels below 40 ng/mL correlate to higher thyroid antibodies. Safe sun exposure remains the optimal vitamin D source, with guidelines suggesting 10-30 minutes of midday sunlight (depending on skin type and latitude) several times weekly. For those requiring supplementation, daily doses of 1000-5000 IU (titrated to maintain levels >40 ng/mL) can support the immune system. Regular monitoring through blood tests is essential, as vitamin D requirements vary significantly based on individual absorption capacity and autoimmune disease activity.

Recent research into selenium plus myo-inositol therapy for thyroid conditions has yielded promising results, but experts caution that several important factors should be considered. First, it’s crucial to understand that individual responses to this treatment can vary significantly. While some patients experienced dramatic improvements in their condition, others saw only modest changes, highlighting the need for personalized treatment approaches.

Another key consideration is the current lack of long-term data. The studies conducted so far have only covered a six-month period, leaving questions about the lifelong impacts of this therapy unanswered. This gap in our knowledge underscores the need for extended research to fully understand the long-term effects and potential benefits or risks associated with prolonged use of combination therapy.

Cost is also an important factor for patients to consider. High-quality supplements required for this treatment could cost an average of $30 to $50 per month, which may be a significant expense for some people.

Despite these caveats, there is compelling evidence for the potential benefits of combination therapy. Selenium and myo-inositol therapy offers statistically significant advantages in key thyroid markers compared to selenium alone, particularly for normalizing TSH levels and reducing thyroid antibodies. This suggests that the combined approach could offer superior results for some patients compared to single-supplement treatments.

Combining selenium and myo-inositol offers a promising approach to managing Hashimoto’s thyroiditis. Its benefits include improved thyroid function, reduced antibody levels, enhanced symptom management, and potentially positive effects on overall metabolic health. While it should not replace standard medical care, this supplement combination may be a valuable adjunct to traditional treatments for Hashimoto’s thyroiditis.

As with any supplement regimen, individuals with Hashimoto’s thyroiditis should consult with their healthcare provider before starting selenium and myo-inositol supplementation. Proper dosing, regular monitoring of thyroid function, and ongoing assessment of overall health are essential to ensure the safe and effective use of these supplements in managing Hashimoto’s thyroiditis.

You can conveniently monitor your thyroid levels – as well as vitamin D – using the convenient Paloma home thyroid test kit. And Paloma’s thyroid care providers can work with you to incorporate supplements like selenium and myo-inositol into your comprehensive treatment plan.

• Hashimoto’s thyroiditis and standard treatment limitations: Millions of Americans struggle with Hashimoto’s, an autoimmune thyroid condition causing fatigue, weight gain, and metabolic issues, and often, standard thyroid hormone replacement therapy isn’t enough to resolve symptoms.
• Selenium’s crucial role in thyroid health: Selenium is essential for thyroid hormone metabolism and antioxidant defense, helping to convert T4 into active T3 and protect against oxidative damage. Supplementing with 100-200 µg/day of selenomethionine can lower thyroid antibodies and slow disease progression.
• Myo-inositol’s impact on thyroid function: Myo-inositol supports iodine regulation and thyroid hormone synthesis, improving TSH receptor sensitivity and reducing elevated TSH levels, with studies recommending 600 mg/day for 6-12 months.
• Synergistic benefits of selenium and myo-inositol: A 2024 study showed that combining these supplements stabilizes TSH levels 42% faster, reduces thyroid antibodies more effectively, and enhances overall thyroid function better and more quickly compared to selenium alone.
• Potential for symptom relief and improved quality of life: Patients taking the combination report faster symptom relief, better energy levels, and enhanced well-being, particularly those with subclinical hypothyroidism or normal thyroid levels.
• Additional health benefits and safety considerations: The combination also supports metabolic health, insulin sensitivity, and inflammation reduction, with a strong safety profile when taken within recommended dosages (not exceeding 400 µg/day of selenium).
• Complementary lifestyle strategies: Managing stress, optimizing gut health, and maintaining a nutrient-rich diet further support thyroid function and immune health, enhancing the effectiveness of selenium and myo-inositol supplementation.