Hashimoto’s thyroiditis is an autoimmune condition that affects thyroid function and overall well being. Selenium plays a vital role in thyroid hormone production and helps reduce oxidative stress and inflammation linked to Hashimoto’s.
Adequate selenium intake may support immune balance, improve thyroid antibody levels, and promote better energy and metabolism. However, not all selenium supplements are created equal in terms of form, absorption, and quality.
Choosing the right option can make a meaningful difference in managing symptoms and supporting long term thyroid health. This guide highlights the top 10 best selenium supplements to help you make an informed and confident choice.
10. Dr. Westin Childs T3 Conversion Booster
The Dr. Westin Childs T3 Conversion Booster is a targeted thyroid‑support formula designed for anyone battling hypothyroidism, Hashimoto’s, or post‑thyroid surgery.
It focuses on the active hormone T3, helping the body produce more triiodothyronine directly in the thyroid gland and in peripheral tissues—something most supplements overlook.
A synergistic blend of zinc, selenium, and guggul extract fuels the deiodinase enzymes that convert T4 into usable T3, while vitamins A and E enhance cellular sensitivity so the hormone can actually do its job.
Adrenal health isn’t ignored; ashwagandha acts as an adaptogen, balancing cortisol and supporting energy levels when the thyroid and adrenal glands are out of sync. Natural iodine from kelp rounds out the mix, safely paired with selenium to protect the gland from oxidative damage.
All of this comes in a clean, hypoallergenic capsule: gluten‑free, dairy‑free, soy‑free, GMO‑free, and free of artificial colors, sweeteners, and preservatives. Made in the USA in a GMP‑certified facility, each batch is third‑party tested for heavy metals, mold, and microbes.
Pros
- Boosts active T3 hormone production naturally
- Enhances T4‑to‑T3 conversion with key minerals
- Supports adrenal health and cortisol balance
- Provides iodine from kelp, safely paired with selenium
- Clean, allergen‑free formula with third‑party testing
Cons
- May interact with thyroid medication doses
- Not a standalone replacement for prescribed therapy
- Requires consistent daily use for best results
9. Micro Selenium Supplements, 500 Softgels
Micro Ingredients Selenium softgels deliver a high‑absorption, 200 mcg dose of L‑Selenomethionine in each coconut‑oil capsule. The bioavailable formula is paired with healthy coconut oil, which helps transport the mineral across cell membranes for optimal uptake.
With 500 softgels per pouch, you get a convenient one‑a‑day serving that supports long‑term antioxidant protection, energy production, heart health, and immune function.
Selenium activates glutathione, one of the body’s most powerful antioxidants, and L‑Selenomethionine is a naturally occurring trace mineral that the body readily recognizes.
These premium, non‑GMO softgels are free from soy, dairy, and gluten, and each batch undergoes third‑party lab testing to ensure safety, purity, and potency.
Pros
- High‑absorption L‑Selenomethionine (200 mcg)
- Coconut‑oil carrier enhances nutrient delivery
- One‑a‑day dose for 500‑day supply
- Supports glutathione‑driven antioxidant defense
- Non‑GMO, soy‑, dairy‑, gluten‑free formula
Cons
- Large bottle may feel excessive for occasional users
- Softgel size could be difficult for some swallowing
- No vegan‑compatible option (contains coconut oil)
8. Dr. Westin Childs – Thyroid+ 120 ct
Raw, freeze‑dried thyroid support from grass‑fed bovine glands delivers a potent, whole‑thyroid blend that’s gentle on the gut and powerful for hormone balance.
Each capsule supplies 150 mg of desiccated thyroid, plus natural iodine from dulse, Irish moss, and bladderwrack, and highly bioavailable selenomethionine to protect the gland and aid T4/T3 production.
The formula is crafted for anyone battling hypothyroidism or Hashimoto’s—women and men alike—offering a daily boost of L‑tyrosine, selenium, iodine, and other essential nutrients.
Made in a GMP‑compliant U.S. facility, every batch is third‑party tested for heavy metals, microbes, and contaminants, and is free of gluten, dairy, soy, GMOs, artificial sweeteners, and preservatives.
Over 80,000 thyroid patients trust Dr. Westin Childs for consistent, high‑quality support, and the flexible dosing (1‑4 capsules per day) lets you tailor the intake to your individual needs.
Pros
- Freeze‑dried, raw thyroid preserves active nutrients
- Grass‑fed bovine source ensures premium quality
- Natural iodine and selenium boost hormone synthesis
- Gluten‑free, dairy‑free, soy‑free, GMO‑free formula
- Third‑party tested for safety and purity
Cons
- May require multiple capsules daily
- Not a substitute for prescription medication
- Strong taste may linger after swallowing
7. Pure Encapsulations Selenium 200
Pure Encapsulations Selenium delivers 200 mcg of high‑quality selenium per capsule, a vital mineral that acts as a co‑factor for glutathione peroxidases. By supporting healthy cellular function, it helps fortify the immune system and maintain robust antioxidant defenses.
The formula also contributes to normal thyroid hormone production, making it a well‑rounded addition to daily nutrition. Each bottle contains 180 vegan, gluten‑free capsules, free from common allergens, artificial additives, and GMOs—just the pure ingredients your body needs.
For optimal absorption, take one capsule with a meal or as directed by a health professional.
Pros
- Supports immune health and cellular resilience
- Boosts antioxidant defenses and thyroid function
- Vegan‑friendly, gluten‑free, allergen‑free formula
- 180‑capsule supply for six‑month convenience
- No artificial colors, flavors, or GMOs
Cons
- May interact with high‑dose thyroid medication
- Requires consistent daily intake for benefits
- Not suitable for those allergic to selenium supplements
Enjoy the peace of mind that comes with Pure Encapsulations’ commitment to purity—only the essential mineral, nothing else.
6. NOW Supplements, Selenium L-Selenomethionine 100 Tablets
Selenium is a vital trace mineral that supports antioxidant defenses, thyroid health, and immune function. NOW’s Selenium comes as L‑Selenomethionine, a highly bio‑available form, delivering a precise 100 µg per tablet.
Sourced from plant‑based ingredients, these tablets are yeast‑free, vegan, soy‑free, non‑GMO, and kosher, making them suitable for a wide range of dietary preferences. Each tablet is easy to swallow and can be taken once or twice daily with food for optimal absorption.
Manufactured in the USA by a family‑owned company with a legacy dating back to 1968, the product is produced under GMP‑certified conditions.
An A‑rated, third‑party certification ensures every batch meets strict standards for potency, stability, and purity, with in‑house ISO/IEC‑accredited labs verifying quality at each step.
Pros
- Highly bio‑available L‑Selenomethionine form
- Precise 100 µg dose per tablet
- Vegan, soy‑free, non‑GMO, kosher certified
- Yeast‑free, gentle on sensitive stomachs
- GMP‑verified, third‑party tested for purity
Cons
- May require two tablets for higher needs
- Not suitable for those avoiding all mineral supplements
- Tablet size may be large for some users
5. NOW Foods Selenium 100mcg 250 Tablets
Selenium (L‑Selenomethionine) 100 mcg tablets from NOW Foods deliver a potent, bio‑available source of this essential trace mineral. Naturally occurring in Brazil nuts, organ meats, seafood, and wheat germ, selenium supports antioxidant defenses, thyroid health, and immune function.
Each tablet is yeast‑free and designed for easy daily use—simply take one tablet once or twice a day with food. The formula is vegan, soy‑free, non‑GMO, and kosher, fitting a wide range of dietary preferences.
Produced under GMP‑certified conditions, the product carries an A‑rated, third‑party certification, and all testing is performed in NOW’s ISO/IEC‑accredited in‑house laboratories to ensure stability, potency, and purity.
Packaged in the USA by a family‑owned company that has been operating since 1968, these 250 tablets offer a reliable, high‑quality supplement for anyone looking to maintain optimal selenium levels.
Pros
- High‑potency 100 mcg per tablet dosage
- Yeast‑free, suitable for sensitive stomachs
- Vegan, soy‑free, non‑GMO, kosher certified
- A‑rated GMP, third‑party quality assurance
- Made in USA by a trusted family brand
Cons
- May require multiple tablets for higher needs
- Not a substitute for a balanced diet
- Tablet size may be large for some users
4. NOW Foods Thyro Support, 30 Day Supply
A balanced thyroid blend from 1 Body delivers 200 µg selenium, 8 mg zinc, iodine and a suite of herbs in every 2‑capsule serving. This all‑in‑one formula supports healthy thyroid function, hormone balance and steady daily energy for both women and men.
The addition of 300 mg L‑tyrosine, vitamin B12 and ashwagandha helps clear occasional brain fog, promoting calm focus during busy days.
Metabolism‑boosting ingredients such as forskolin, schisandra, copper and zinc work together to aid weight‑management goals while maintaining consistent energy levels.
An adaptogen‑rich profile with ashwagandha and schisandra assists the body in handling occasional stress, supporting mood and emotional wellness.
Made in the USA, the blend is gluten‑free, soy‑free and dairy‑free, offering a clean, reliable supplement you can trust for everyday thyroid care.
Pros
- Supports hormone balance and daily energy
- Enhances mental clarity and reduces brain fog
- Boosts metabolism and steady weight management
- Adaptogen blend helps stress adaptation
- Clean, allergen‑free formula made in USA
Cons
- Requires two capsules daily for full dose
- May interact with thyroid medication; consult physician
- Not suitable for pregnant or nursing women without guidance
3. Pure Encapsulations Selenium 200 mcg Capsules
Pure Encapsulations Selenium delivers 200 µg of high‑quality selenium per vegan capsule, a critical trace mineral that acts as a co‑factor for glutathione peroxidases—your body’s natural antioxidant enzymes.
By bolstering antioxidant defenses, it helps protect cells from oxidative stress while also supporting healthy thyroid hormone production.
Each bottle contains 60 capsules, formulated without common allergens, artificial additives, or GMOs, making it a clean choice for sensitive diets.
Take one capsule with a meal, or follow your practitioner’s guidance, to maintain optimal cellular function and give your immune system the extra support it needs during busy seasons or recovery periods.
The Pure Difference means you get only what matters: pure, clinically tested ingredients and a commitment to transparency.
Whether you’re looking to reinforce your immune resilience, support thyroid health, or simply fill a nutritional gap, these vegan‑friendly capsules fit seamlessly into a balanced supplement routine.
Pros
- Supports immune system and cellular health
- Enhances antioxidant defenses against oxidative stress
- Promotes healthy thyroid hormone production naturally
- Vegan, gluten‑free, and free from common allergens
- No artificial colors, flavors, or GMOs
Cons
- May interact with high‑dose vitamin E supplements
- Not a substitute for a balanced diet
- Requires daily intake for optimal benefit
2. Purevit Thyro Support 60 Capsules
Purevit Advanced Thyroid Support is a vegetarian‑friendly, iodine‑free formula designed to nurture thyroid health at the cellular level.
The blend harnesses the potent antioxidant power of Nigellin black cumin extract together with rosemary extract and kaempferol, helping to maintain thyroid‑cell redox balance and protect tissue integrity.
Guggul extract works behind the scenes to promote the conversion of T4 into the active T3 hormone, ensuring your metabolism runs smoothly.
Selenium is delivered as highly bioavailable selenomethionine, while myo‑inositol supports thyroid‑immune communication—an especially valuable combination for women dealing with Hashimoto’s or hypothyroidism.
The supplement also targets inflammatory pathways and boosts glutathione peroxidase activity, fostering a healthier immune response and stable hormone levels.
With 60 easy‑to‑swallow capsules, Purevit offers a convenient, daily dose of comprehensive thyroid support without the risk of iodine sensitivity.
Pros
- Antioxidant blend protects thyroid cell health
- Guggul enhances conversion of T4 to T3
- Iodine‑free, safe for iodine‑sensitive users
- Vegetarian formula, suitable for plant‑based diets
- Selenium + myo‑inositol synergize immune support
Cons
- May require several weeks for noticeable effects
- Not a substitute for prescribed thyroid medication
- Contains soy lecithin, not suitable for soy‑allergic individuals
1. Thorne Selenium 200
Thorne’s Selenium 200 mcg delivers a potent antioxidant boost in a convenient, vegan‑friendly capsule. Each dose supplies the exact amount of selenium needed to support normal thyroid function, helping the gland convert thyroid hormones efficiently.
As a powerful antioxidant, selenium combats oxidative stress from everyday toxins, smoking, alcohol, and stress, which can translate to clearer skin, stronger hair, and sharper cognitive performance.
Because selenium is an essential micronutrient, consistent supplementation helps maintain overall health and wellness. Thorne backs its quality with third‑party testing and certification, guaranteeing that what’s on the label matches what’s inside.
The brand is a favorite among elite athletes, partnered with U.S. National Teams, and ranked the #1 recommended clinical brand by health‑care practitioners in the 2023 survey—so you can trust you’re getting a product that champions and professionals rely on.
Pros
- Supports normal thyroid function in healthy adults
- Powerful antioxidant reduces oxidative damage
- Promotes healthy skin, hair, and cognition
- Third‑party certified for label accuracy
- Trusted by athletes and health‑care practitioners
Cons
- May be unnecessary for those with adequate selenium
- Not suitable for individuals on selenium‑restricted diets
- Requires consistent daily intake for benefits
Frequently Asked Questions
What dosage of selenium is recommended for Hashimoto’s thyroiditis?
A typical therapeutic dose for Hashimoto’s is 200 µg of selenium per day, usually taken as selenomethionine. This amount has been shown in clinical studies to reduce thyroid antibody levels without causing toxicity.
Always consult your healthcare provider before starting supplementation, especially if you are taking other medications or have a pre‑existing health condition.
Which form of selenium is most effective for supporting thyroid health?
Selenomethionine is the preferred form because it is well‑absorbed (≈90% bioavailability) and can be stored in body tissues, providing a steady supply to the thyroid. Other forms such as sodium selenite are less efficiently utilized and may be more irritating to the gastrointestinal tract.
Are there any safety concerns or interactions to watch for when taking selenium supplements?
- Upper limit: Do not exceed 400 µg per day (the tolerable upper intake level) to avoid selenosis, which can cause hair loss, nail brittleness, and gastrointestinal upset.
- Interactions: Selenium can interact with antithyroid drugs (e.g., methimazole) and antioxidant supplements like high‑dose vitamin E, potentially altering their effectiveness.
- Medical conditions: People with autoimmune diseases, kidney disease, or a history of cancer should discuss selenium use with a physician, as the supplement may affect disease processes.
Bottom line: Choose a high‑quality selenomethionine supplement at 200 µg daily, monitor your response, and keep your doctor in the loop.
Conclusion
Choosing the right selenium supplement for Hashimoto’s hinges on quality, bioavailability, and a formulation that supports thyroid health without unnecessary additives.
Prioritizing products that use organic selenium sources, such as selenomethionine, and that are third‑party tested ensures you receive a consistent, effective dose.
Pairing selenium with complementary nutrients like iodine and vitamin D can further enhance thyroid function, while a clean label reduces the risk of irritation.
By focusing on these core principles—purity, proven absorption, and thoughtful synergy—you can confidently support your autoimmune thyroid management and promote overall wellbeing.
