10 Best Selenium Supplements (2026) Reviewed
Selenium is an essential trace mineral that plays a critical role in thyroid function, immune health, and antioxidant defense. Despite being needed in only small amounts, many people don’t get adequate selenium from their diet alone—particularly those living in regions with selenium-depleted soil or following restrictive diets.
The challenge when shopping for selenium supplements lies in choosing the right form. Selenomethionine offers superior absorption compared to inorganic forms like sodium selenite, while some formulas combine multiple selenium types for comprehensive support. Quality matters significantly with selenium supplements, as third-party testing ensures accurate dosing—critical for a mineral where the upper tolerable limit (400 mcg) isn’t far above the recommended daily amount.
We researched dozens of selenium supplements, cross-referenced third-party testing data from ConsumerLab and other review sites, verified Amazon ASINs, and evaluated each product’s form, quality certifications, and value. Here are the 10 best selenium supplements for 2026.
Table of Contents
- Quick Comparison Table
- Best by Selenium Form
- Individual Product Reviews
- Buying Guide
- How to Take Selenium
- Potential Benefits
- Safety Considerations
- FAQ
- Bottom Line
Quick Comparison Table
| Product | Form | Serving Size | Key Differentiator | Best For | Winner |
|---|---|---|---|---|---|
| NOW Foods Selenium | L-Selenomethionine | 200 mcg / 1 capsule | GMP certified, excellent value | Most people | 🏆 TOP PICK |
| Pure Encapsulations Selenium | Selenomethionine | 200 mcg / 1 capsule | Hypoallergenic formula | Sensitive individuals | 🥇 Best Premium |
| Thorne Selenium | L-Selenomethionine | 200 mcg / 1 capsule | NSF Certified for Sport | Athletes | 🥇 Best for Athletes |
| Life Extension Super Selenium Complex | 3 selenium forms + Vitamin E | 200 mcg / 1 capsule | Multi-form comprehensive formula | Advanced users | 🥇 Best Multi-Form |
| Nutricost Selenium | L-Selenomethionine | 200 mcg / 1 capsule | 240-count bottle, best value | Budget shoppers | 🥇 Best Value |
| Bronson Selenium | Albion Chelated | 200 mcg / 1 capsule | Superior absorption technology | Absorption concerns | 🥇 Best Chelated |
| Solgar Yeast-Free Selenium | L-Selenomethionine | 200 mcg / 1 tablet | Glass bottle, 250-count | Long-term users | |
| Solaray Yeast-Free Selenium | L-Selenomethionine | 200 mcg / 1 vegcap | Eco-friendly packaging | Eco-conscious buyers | 🥇 Best Eco-Friendly |
| Bluebonnet Selenium | L-Selenomethionine | 200 mcg / 1 capsule | Kosher certified, glass bottle | Quality-focused buyers | |
| Nature’s Way Selenium | L-Selenomethionine | 200 mcg / 1 capsule | 50+ year trusted brand | Brand loyalists |
Best by Selenium Form
Understanding the different forms of selenium helps you choose the right supplement for your needs. Here’s how the main forms compare:
Selenomethionine (L-Selenomethionine)
This organic form binds selenium to the amino acid methionine, mimicking how selenium appears naturally in foods like Brazil nuts and legumes. Research suggests selenomethionine offers superior absorption compared to inorganic forms, with studies showing it has better bioavailability than sodium selenite. This is the most popular form in high-quality supplements.
Best options: NOW Foods, Pure Encapsulations, Thorne, Nutricost
Selenium Yeast
Selenium-enriched yeast provides selenium in a food-based matrix that some research suggests may be well-utilized by the body. However, this form isn’t suitable for those with yeast sensitivities or allergies.
Best option: Life Extension (uses yeast-derived forms in its complex)
Chelated Selenium (Selenium Glycinate)
Chelated minerals are bound to amino acids to potentially enhance absorption and reduce digestive discomfort. Albion Minerals is the leading manufacturer of chelated selenium.
Best option: Bronson Selenium (uses Albion chelated selenium)
Multi-Form Complexes
Some supplements combine multiple selenium forms to provide a broader spectrum of selenium types, potentially offering benefits from each form’s unique properties.
Best option: Life Extension Super Selenium Complex (3 forms plus Vitamin E)
Individual Product Reviews
NOW Foods Selenium 200 mcg — Best Overall
A trusted, affordable option that delivers bioavailable selenomethionine with extensive quality certifications and an excellent track record.
NOW Foods has been a family-owned supplement company since 1968, and their selenium supplement exemplifies their commitment to quality at affordable prices. The formula uses L-selenomethionine, the highly bioavailable organic form that research indicates is better absorbed than inorganic selenium forms like sodium selenite.
What sets NOW apart is their comprehensive quality program. The product is manufactured in a GMP-certified facility with NPA A-rated certification, meaning every aspect of manufacturing has been examined. Their in-house laboratories hold ISO/IEC accreditation for testing stability, potency, and formulation accuracy. The yeast-free formula works well for those with sensitivities, and the vegan capsules suit various dietary preferences.
Key Specifications:
- Selenium: 200 mcg (364% DV) from L-Selenomethionine
- Capsules per bottle: 180
- Certifications: GMP certified, Non-GMO, Vegan, Kosher
- Other ingredients: Rice flour, hypromellose capsule, stearic acid
Considerations: Contains rice flour as a filler, which some ultra-purists may prefer to avoid, though it’s generally well-tolerated.
Pure Encapsulations Selenomethionine — Best Premium
The gold standard for those with sensitivities, featuring a hypoallergenic formula free from common allergens and unnecessary additives.
Pure Encapsulations has built its reputation on producing supplements that healthcare practitioners trust for their sensitive patients. Their selenium supplement contains just selenomethionine in a hypoallergenic vegetarian capsule with minimal additional ingredients—exactly what you’d expect from a practitioner-grade brand.
The formula is free from wheat, eggs, tree nuts, peanuts, gluten, artificial colors, flavors, sweeteners, coatings, GMOs, and unnecessary binders or preservatives. This makes it an excellent choice for those with multiple food sensitivities or autoimmune conditions like Hashimoto’s thyroiditis, where selenium supplementation is often recommended but allergen concerns are paramount.
Key Specifications:
- Selenium: 200 mcg (364% DV) from Selenomethionine
- Capsules per bottle: 60
- Certifications: Non-GMO, Vegan, Gluten-Free
- Other ingredients: Hypoallergenic plant fiber, vegetarian capsule, ascorbyl palmitate
Considerations: Higher per-capsule cost than budget options, and the smaller bottle size means more frequent reordering for long-term users.
Thorne Selenium — Best for Athletes
NSF Certified for Sport and trusted by professional sports teams, Thorne delivers pharmaceutical-grade purity for competitive athletes.
Thorne has positioned itself as the supplement brand of choice for elite athletes, partnering with over 100 professional sports teams and serving as an official partner of U.S. National Teams. Their selenium supplement carries NSF Certified for Sport designation, meaning it’s been tested to verify label claims and screened for nearly 300 substances banned by major athletic organizations.
Beyond athletic certification, Thorne’s commitment to purity extends to their manufacturing process. The simple formula contains L-selenomethionine with only microcrystalline cellulose and a hypromellose capsule—no unnecessary fillers, binders, or artificial ingredients. This clean approach makes it the top choice not just for athletes but for anyone prioritizing purity.
Key Specifications:
- Selenium: 200 mcg from L-Selenomethionine
- Capsules per bottle: 60
- Certifications: NSF Certified for Sport, Gluten-Free, Dairy-Free, Soy-Free
- Other ingredients: Microcrystalline cellulose, hypromellose capsule
Considerations: Premium pricing reflects the extensive third-party testing and certifications.
Life Extension Super Selenium Complex — Best Multi-Form
A comprehensive formula combining three distinct selenium forms with vitamin E for enhanced antioxidant support and longevity benefits.
Life Extension takes a science-forward approach to selenium supplementation by combining three different selenium forms: L-selenomethionine (50 mcg), sodium selenite (50 mcg), and Se-Methyl L-Selenocysteine (100 mcg). The rationale is that different selenium forms may be utilized differently by the body, and combining them may provide more comprehensive support.
The addition of vitamin E (as d-alpha tocopheryl succinate) complements selenium’s antioxidant properties, as research suggests these nutrients may work synergistically. This formula is particularly popular among Life Extension’s longevity-focused customer base, given the company’s emphasis on research-backed approaches to healthy aging.
Key Specifications:
- Selenium: 200 mcg total (3 forms)
- Vitamin E: 20.1 mg (134% DV)
- Capsules per bottle: 100
- Certifications: Non-GMO, Gluten-Free, Vegetarian
- Other ingredients: Microcrystalline cellulose, vegetable capsule, stearic acid, silica
Considerations: Contains vitamin E, which may not be desired by everyone; check with your healthcare provider if you take blood thinners.
Nutricost Selenium — Best Value
An 8-month supply of bioavailable selenomethionine at an unbeatable price point without sacrificing quality standards.
Nutricost has carved out a niche by offering clean, straightforward supplements at remarkably competitive prices. Their selenium supplement delivers 200 mcg of L-selenomethionine—the same highly absorbable form used by premium brands—in a 240-capsule bottle that lasts most users 8 months.
Despite the budget pricing, Nutricost maintains respectable quality standards. All products are manufactured in a GMP-compliant, FDA-registered facility and undergo third-party testing by ISO-accredited laboratories. The formula is non-GMO, gluten-free, and vegan-friendly, making it accessible to most dietary preferences.
Key Specifications:
- Selenium: 200 mcg (364% DV) from L-Selenomethionine
- Capsules per bottle: 240
- Certifications: Non-GMO, Gluten-Free, Vegan, Third-Party Tested
- Other ingredients: Rice flour, hypromellose capsule, dicalcium phosphate
Considerations: Less established brand compared to legacy supplement companies; contains dicalcium phosphate as a filler.
Bronson Selenium — Best Chelated Form
Features Albion chelated selenium for superior absorption, backed by over 60 years of supplement manufacturing experience.
Bronson Vitamins was founded in 1960 by pharmacists who witnessed firsthand the benefits of supplementation with their patients. Their selenium supplement stands out by using Albion Minerals’ patented chelated amino acid complex, which binds selenium to amino acids for potentially enhanced absorption, stability, and digestibility.
Albion Minerals holds over 150 patents for their chelation technology and is recognized as the premier manufacturer of chelated minerals. For those who have experienced digestive issues with other selenium forms or who want to maximize absorption, Bronson’s chelated formula may be worth the investment.
Key Specifications:
- Selenium: 200 mcg from Albion Chelated Amino Acid Complex
- Capsules per bottle: 250
- Certifications: Non-GMO, Gluten-Free, Soy-Free, Yeast-Free
- Other ingredients: Modified cellulose capsule, microcrystalline cellulose, magnesium stearate, silicon dioxide
Considerations: Contains magnesium stearate, which some purists prefer to avoid (though it’s generally recognized as safe).
Solgar Yeast-Free Selenium — Best for Long-Term Supply
A heritage brand since 1947 offering a generous 250-count bottle in protective amber glass packaging.
Solgar has been manufacturing supplements for nearly 80 years, establishing themselves as one of the most trusted names in the industry. Their yeast-free selenium uses L-selenomethionine in tablet form, packaged in their signature amber glass bottles that protect against light degradation and are made from 50% recycled glass.
The 250-tablet bottle provides excellent value for long-term users, and Solgar’s commitment to quality—including avoiding artificial colors, flavors, sweeteners, and preservatives—has earned them a loyal following among health-conscious consumers.
Key Specifications:
- Selenium: 200 mcg (364% DV) from L-Selenomethionine
- Tablets per bottle: 250
- Certifications: Non-GMO, Vegan, Gluten-Free, Dairy-Free, Kosher
- Other ingredients: Dicalcium phosphate, microcrystalline cellulose, silica, vegetable magnesium stearate
Considerations: Tablet form rather than capsule may be harder for some to swallow; some users report a slight odor.
Solaray Yeast-Free Selenium — Best Eco-Friendly
Combines quality selenomethionine with environmentally responsible packaging made from ocean and landfill plastics.
Solaray stands out by prioritizing environmental sustainability alongside supplement quality. Their bottles are made from 100% post-consumer recycled (PCR) resin, helping keep plastic out of oceans and landfills. The company has also installed solar panels at their Ogden, Utah facility to reduce their carbon footprint.
The formula itself is straightforward and effective: yeast-free L-selenomethionine in easy-to-swallow vegcaps. Solaray has been producing supplements since 1973 and maintains their own manufacturing facility for quality control.
Key Specifications:
- Selenium: 200 mcg (364% DV) from L-Selenomethionine
- Capsules per bottle: 90
- Certifications: Vegan, Eco-Friendly Packaging
- Other ingredients: Whole rice concentrate, cellulose, vegetable cellulose capsule, rice bran extract
Considerations: Smaller bottle size means more frequent reordering; eco-friendly packaging may be less protective than glass.
Bluebonnet Selenium — Best for Clean Ingredients
A meticulously clean formula free from all major allergens, housed in sustainable amber glass packaging.
Bluebonnet Nutrition emphasizes “clean nutrition” with formulas free from an extensive list of allergens and additives. Their selenium supplement contains no milk, egg, fish, shellfish, tree nuts, peanuts, wheat, soybeans, corn, yeast, gluten, barley, rice, sodium, or sugar—making it one of the cleanest options available.
The company sources premium raw materials directly from growers, farmers, and suppliers, and manufactures in a cGMP-compliant, ISO-certified facility with rigorous testing protocols. The recyclable amber glass bottle supports their sustainability initiatives while protecting product integrity.
Key Specifications:
- Selenium: 200 mcg (364% DV) from L-Selenomethionine
- Capsules per bottle: 90
- Certifications: Non-GMO, Vegan, Kosher, Gluten-Free, Dairy-Free, Soy-Free
- Other ingredients: Vegetable cellulose, hypromellose capsule, vegetable magnesium stearate
Considerations: Higher per-capsule cost; smaller bottle requires more frequent purchasing.
Nature’s Way Selenium — Best Heritage Brand
A trusted name for over 50 years offering reliable, straightforward selenium supplementation.
Nature’s Way has been helping people “find their way to wellness” since the 1960s, making them one of the longest-standing supplement brands available. Their selenium supplement takes a no-frills approach: L-selenomethionine in a simple gelatin capsule with minimal additional ingredients.
The formula is free from sugar, salt, wheat, corn, soy, dairy, artificial colors, flavors, and preservatives. While not flashy, Nature’s Way’s consistent quality and wide availability (including most grocery stores and pharmacies) make it a reliable choice for those who value accessibility and brand recognition.
Key Specifications:
- Selenium: 200 mcg (364% DV) from L-Selenomethionine
- Capsules per bottle: 100
- Certifications: Gluten-Free
- Other ingredients: Cellulose, gelatin capsule
Considerations: Uses gelatin capsule (not suitable for vegans/vegetarians); fewer certifications than some competitors.
Buying Guide: What to Look For in a Selenium Supplement
Form of Selenium
Selenomethionine (or L-selenomethionine) is generally considered the most bioavailable form. Research suggests it’s better absorbed than inorganic forms like sodium selenite. If you want a multi-form approach, look for products combining selenomethionine with other selenium types.
Dosage Considerations
Most supplements provide 200 mcg per serving, which is 364% of the Daily Value. While this exceeds the 55 mcg RDA, it remains well under the 400 mcg upper tolerable limit. Some people may prefer lower doses (100 mcg) to account for dietary selenium intake—particularly if they regularly eat Brazil nuts, seafood, or organ meats.
Quality Certifications to Look For
- GMP Certification: Ensures good manufacturing practices
- Third-Party Testing: Independent verification of potency and purity (look for NSF, USP, or ConsumerLab certification)
- Non-GMO: Verifies ingredients aren’t genetically modified
- Allergen-Free Claims: Important if you have sensitivities
Red Flags to Avoid
- Products without clear labeling of selenium form
- Excessive dosages (above 400 mcg)
- Added ingredients with no clear purpose
- Brands without transparent manufacturing information
- Products making disease treatment or cure claims
Capsules vs. Tablets
Capsules generally dissolve faster and may be easier to swallow. Tablets often cost less and have longer shelf stability. Vegan capsules (made from cellulose or hypromellose) are available for those avoiding gelatin.
How to Take Selenium
Recommended Dosage
The Recommended Dietary Allowance (RDA) for selenium is 55 mcg daily for most adults. Pregnant women need 60 mcg, and lactating women need 70 mcg. Most supplements provide 100-200 mcg, which accounts for variable dietary intake and absorption differences.
Best Time to Take
Selenium is best absorbed when taken with food, particularly a meal containing some fat. Most manufacturers recommend taking selenium with meals to enhance absorption and reduce potential stomach discomfort.
Different Forms, Same Approach
Whether taking capsules, tablets, or liquid selenium, the same general guidelines apply: take with food, stay consistent with timing, and don’t exceed recommended doses.
Duration and Cycling
Selenium can be taken continuously as a daily supplement. Unlike some supplements, there’s no established need to cycle selenium. However, periodic blood testing can help ensure levels remain optimal, particularly for those taking higher doses or with thyroid conditions.
Potential Benefits of Selenium Supplementation
Thyroid Function Support
The thyroid gland contains more selenium per gram of tissue than any other organ. Selenium is essential for converting the thyroid hormone T4 (thyroxine) to its active form T3 (triiodothyronine). Research published in the Journal of Clinical Endocrinology & Metabolism suggests selenium supplementation may support healthy thyroid function, particularly in those with autoimmune thyroid conditions.
Antioxidant Defense
Selenium is a crucial component of selenoproteins, including glutathione peroxidases—powerful antioxidant enzymes that help protect cells from oxidative damage. This antioxidant activity may contribute to healthy aging and cellular protection.
Immune Function
Research suggests selenium may play a role in immune system function. Selenium deficiency has been associated with impaired immune responses, while adequate selenium status may support the body’s natural defense mechanisms.
Reproductive Health
Selenium is important for male reproductive health, as it’s concentrated in the testes and plays a role in sperm formation. Some research suggests selenium may support healthy fertility in both men and women.
Safety Considerations
Potential Side Effects
At recommended doses (up to 200 mcg), selenium is generally well-tolerated. However, some people may experience garlic-like breath odor, metallic taste, or mild digestive upset. These effects are typically temporary.
Signs of Excess (Selenosis)
Consuming more than 400 mcg daily over time may lead to selenium toxicity, characterized by hair loss, nail brittleness, gastrointestinal issues, skin rashes, fatigue, and neurological symptoms. This is why staying within recommended doses is crucial.
Who Should Avoid or Use Caution
- Those with adequate or high selenium status (get tested first)
- People taking blood thinners (selenium may enhance effects)
- Those on certain cholesterol medications
- Individuals undergoing chemotherapy (consult oncologist)
- People with kidney disease (may accumulate selenium)
Drug Interactions
Selenium may interact with certain medications, including anticoagulants, immunosuppressants, and some chemotherapy drugs. Always consult your healthcare provider before starting selenium supplementation if you take prescription medications.
When to Consult a Healthcare Provider
Speak with a healthcare professional before taking selenium if you’re pregnant or breastfeeding, have thyroid disorders, kidney disease, or immune conditions, or take prescription medications.
Frequently Asked Questions
How much selenium should I take daily?
The RDA is 55 mcg for most adults. Supplements typically provide 100-200 mcg to account for variable dietary intake. Don’t exceed 400 mcg daily from all sources combined (food plus supplements) to avoid potential toxicity.
What’s the best form of selenium to take?
Selenomethionine (L-selenomethionine) is generally considered the most bioavailable form. Research suggests it’s better absorbed than inorganic forms like sodium selenite. Look for products specifying selenomethionine on the label.
Can I get enough selenium from food alone?
It depends on your diet and where your food is grown. Brazil nuts are exceptionally high in selenium (one nut may contain 70-90 mcg), while seafood, organ meats, and whole grains are good sources. However, soil selenium levels vary greatly by region, affecting plant-based sources.
Is selenium safe to take every day?
Yes, at recommended doses (up to 200 mcg), selenium can be taken daily as a long-term supplement. It’s an essential mineral the body needs continuously. Just don’t exceed the 400 mcg upper limit.
Should I take selenium with or without food?
Taking selenium with food, particularly a meal containing some fat, may enhance absorption and reduce potential stomach discomfort. Most manufacturers recommend taking it with meals.
Does selenium help with thyroid problems?
Selenium is essential for thyroid hormone metabolism. Some research suggests it may support thyroid health, particularly in those with autoimmune thyroid conditions like Hashimoto’s thyroiditis. However, consult your healthcare provider for personalized advice.
What’s the difference between yeast-based and yeast-free selenium?
Yeast-based selenium is derived from selenium-enriched yeast, providing selenium in a food-matrix form. Yeast-free selenium (typically selenomethionine) is produced without yeast, making it suitable for those with yeast sensitivities. Both forms can be effective.
Can taking too much selenium be harmful?
Yes. Chronic intake above 400 mcg daily may cause selenosis—symptoms include hair loss, nail brittleness, garlic breath, fatigue, and neurological issues. Stick to recommended doses and consider your dietary selenium intake.
How long does it take for selenium supplements to work?
Selenium is absorbed relatively quickly, but noticeable effects (if any) may take several weeks to months of consistent supplementation. Blood selenium levels typically stabilize within 2-3 months of regular supplementation.
Can I take selenium with other supplements?
Selenium is commonly taken alongside other antioxidants like vitamin E, as they may work synergistically. It’s also found in many multivitamins. However, avoid combining multiple high-dose selenium products that might exceed safe limits.
Bottom Line: Our Top Recommendations
For most people: NOW Foods Selenium offers the best combination of quality, bioavailability, and value. The L-selenomethionine form is well-absorbed, the GMP certification provides quality assurance, and the price point makes it accessible for long-term use.
For those with sensitivities: Pure Encapsulations Selenium provides practitioner-grade purity with a hypoallergenic formula free from common allergens and unnecessary additives.
For athletes requiring tested supplements: Thorne Selenium carries NSF Certified for Sport designation, ensuring it’s safe for competitive athletes subject to drug testing.
For budget-conscious buyers: Nutricost Selenium delivers excellent value with an 8-month supply of quality selenomethionine at an unbeatable price.
For comprehensive selenium support: Life Extension Super Selenium Complex provides three forms of selenium plus vitamin E for those seeking a multi-form approach to selenium supplementation.
