The 10 Best Selenium Supplements, According to a Dietitian

Selenium is a trace mineral vital to health in multiple ways. Your body incorporates selenium into specialized proteins known as selenoproteins.

Selenoproteins play critical roles such as aiding thyroid hormone production. They also possess antioxidant and anti-inflammatory properties (1 ).

Low selenium status has been linked to several adverse health outcomes, including weakened immune response and a higher risk of anxiety, infertility, cardiovascular disease, and even mortality (2 ).

You must obtain selenium from food. It occurs in both animal and plant sources such as meat, grains, Brazil nuts, fish, and eggs. However, selenium levels in foods fluctuate depending on the selenium content of the soil where they’re grown (3 ).

In 2020, the Food and Drug Administration (FDA) lowered the recommended Daily Value (DV) for selenium from 70 mcg to 55 mcg (4 ).

Certain groups — including those on vegan diets, people living with HIV, and individuals with kidney failure on dialysis — face a greater risk of selenium deficiency (3 , 5 ).

Research also indicates selenium supplementation may help enhance immune function in some groups and ease symptoms in certain conditions like autoimmune thyroid disease (6 , 7 ).

For these reasons, many opt to take selenium either as a single-nutrient supplement or as part of a multinutrient formula containing selenium.

A quick look at our picks of the best selenium supplements

• Best selenium capsules:Klaire Labs Seleno Met, Pure Encapsulations Selenomethionine, NOW Foods Selenium (yeast-free), and Bluebonnet Selenium
• Best for immune support:NOW Foods EpiCor Plus Immunity and Carlson Labs ACES + Zinc
• Best for prostate health:Pure Encapsulations SP Ultimate
• Best multinutrient supplements:Thorne Trace Minerals, Vital Nutrients Multi-Nutrients (no iron or iodine), and Nordic Naturals Multi Minerals

How we chose the best selenium supplements

The brands included here are commonly trusted by clinicians and uphold strict quality and safety practices for their supplements.

Many of the products below provide selenium as selenomethionine, which tends to be absorbed better than other supplement forms like sodium selenite (3 , 8 , 9 ).

When buying supplements, it’s wise to choose reputable companies and high-quality products.

We evaluated selenium supplements using the following criteria:

• Quality. Products undergo testing for purity and quality, ideally by third-party labs.
• Selenium type. Preference for formulations containing selenomethionine for improved absorption.
• Dose. Sufficient and appropriate selenium amounts per serving.
• Price. Options for various budgets were included.
• Vetting. All selections meet HealthEH’s medical and business vetting standards.

A note on price

Price ranges are shown with dollar signs ($–$$$). One dollar sign denotes more budget-friendly options; three dollar signs indicate pricier choices.

Typical costs vary from $0.13–$1.62 per serving, or about $13.95–$97.70 per bottle, depending on where you shop.

Serving suggestions usually range from 1–4 capsules daily.

Pricing guide

• $ = under $0.25 per serving
• $$ = $0.25–$0.50 per serving
• $$$ = over $0.50 per serving

Best selenium capsules

Selenium is most frequently sold in capsule form. Below are some top capsule options available.

Klaire Labs Seleno Met

• Price: $
• Dose: 1 capsule (200 mcg of selenium, or 364% of the DV)

Klaire Labs is a respected brand that produces professional-grade supplements in line with the FDA’s current good manufacturing practices (CGMPs).

CGMPs require manufacturers to take measures ensuring their products are safe and effective.

Seleno Met offers selenium as L-selenomethionine, a form shown to be absorbed better than several other supplemental forms (3 , 8 , 9 ).

Seleno Met is free from common allergens including casein, shellfish, tree nuts, gluten, soy, and corn, and contains no artificial colors, flavors, or preservatives.

Each capsule contains 200 mcg of selenium.

Pros

• budget-friendly
• contains a highly bioavailable selenium form

Cons

• no explicit third-party testing info on the Klaire Labs site (though the brand follows FDA CGMPs)

Pure Encapsulations Selenomethionine

• Price: $
• Dose: 1 capsule (200 mcg of selenium, or 364% of the DV)

Pure Encapsulations is widely used by healthcare practitioners. The company surpasses United States Pharmacopeia (USP) standards for supplement manufacturing and adheres to CGMP procedures (10).

The brand also independently tests for potency, contaminants, and allergens, and its products are certified gluten-free and non-GMO (10).

Each capsule supplies 200 mcg of selenium.

Pros

• meets and exceeds USP standards
• bioavailable form of selenium
• inexpensive

Cons

• may be difficult to find in brick-and-mortar stores but readily available online

NOW Foods Selenium (yeast-free)

• Price: $
• Dose: 1 capsule (200 mcg of selenium, or 364% of the DV)

NOW Foods is known for offering quality dietary supplements. NOW’s selenium product is available in many natural food stores and some larger grocery chains.

The company follows CGMPs for the supplement industry and its products are certified non-GMO.

NOW is also certified by Underwriters Laboratories (UL), an independent testing body that evaluates manufacturing standards.

NOW’s yeast-free selenium uses L-selenomethionine and is free from common allergens like gluten and soy.

Each capsule provides 200 mcg of selenium.

Pros

• UL Dietary Supplement Certification
• affordable

Cons

• manufactured in facilities where cross-contamination is possible despite being free of certain allergens

Bluebonnet Selenium

• Price: $
• Dose: 1 capsule (200 mcg of selenium, or 364% of the DV)

Bluebonnet is another widely available brand found in many grocery and specialty retailers.

Bluebonnet holds NSF GMP registration, which verifies compliance with good manufacturing practice standards for label claims, identity, quality, and purity.

The brand’s selenium is kosher, certified vegan, soy-free, and gluten-free, and supplies selenomethionine for effective absorption.

One capsule contains 200 mcg of selenium.

Pros

• NSF GMP-registered
• cost-effective

Cons

• only select Bluebonnet products (for example, some fish oils) are subject to third-party testing

Best selenium supplements for immune support

Selenium is crucial for a properly functioning immune system (11 ).

Many immune support supplements combine selenium with other key immune nutrients such as vitamin C and zinc (12 ).

Below are some top picks for selenium-containing supplements aimed at supporting immunity.

NOW Foods EpiCor Plus Immunity

• Price: $$
• Dose: 1 capsule (35 mcg of selenium, or 64% of the DV)

NOW Foods EpiCor Plus Immunity combines selenium with vitamin D3, zinc, and vitamin C — nutrients known to support immune health.

It also includes EpiCor, a yeast-derived ingredient from Saccharomyces cerevisiae.

Some small, limited studies (some industry-sponsored) suggest EpiCor may reduce inflammation and support immune responses (13 , 14 ).

However, these studies had limitations such as small sample sizes and some animal testing. More research is needed to better establish EpiCor’s effects in humans.

Pros

• provides multiple nutrients important for immunity

Cons

• limited evidence supporting EpiCor’s immune benefits
• relatively costly

Carlson Labs ACES + Zinc

• Price: $$
• Dose: 2 softgels (100 mcg of selenium, or 182% of the DV)

Carlson Labs ACES + Zinc supplies 100 mcg of selenium along with zinc and vitamins A, C, and E. It also delivers 50 mg of calcium per serving.

These nutrients are important for immune wellbeing (12 ).

This product may suit people seeking additional micronutrient support, but it’s not ideal for everyone.

Notably, it contains a very large amount of vitamin E — over 1,000% of the DV. Some studies indicate that long-term high-dose vitamin E supplementation might raise prostate cancer risk in otherwise healthy men (15 ).

Therefore, men with prostate cancer or a family history of it should consult a clinician before using this product.

Carlson’s website states their supplements are tested by an FDA-registered lab for potency and quality, though it’s not clear if third-party testing is consistently used.

Pros

• offers a combination of nutrients relevant to immune support

Cons

• contains a very high vitamin E dose, which may be unsuitable or unsafe for some individuals
• includes gelatin and beeswax, making it inappropriate for vegans and some vegetarians

Best selenium supplement for prostate health

Some studies link selenium supplementation to improved prostate health and a reduced prostate cancer risk in men with low selenium levels (16 , 17 ).

However, other research has associated selenium supplements with higher-grade prostate cancer or found no protective effect (18 ).

It appears selenium’s impact on prostate health may vary by baseline selenium status, genetics, and other variables, and benefits may be limited to certain individuals.

If you’re considering selenium for prostate health or cancer prevention, consult a healthcare provider to determine if it’s safe and suitable for you.

Pure Encapsulations SP Ultimate

• Price: $$$
• Dose: 3 capsules (70 mcg of selenium, or 127% of the DV)

Pure Encapsulations SP Ultimate is formulated to support male reproductive and prostate health.

It blends selenium (as yeast-bound L-selenomethionine, Selenomax) with saw palmetto, zinc, lycopene, curcumin, green tea extract, and other ingredients that may help prostate health (19 , 20 , 21 , 22 , 23 ).

Three capsules supply 70 mcg of selenium (100% of the DV).

Pros

• NSF GMP-registered
• exceeds USP manufacturing standards
• contains a blend of ingredients that may support prostate health
• gluten-free

Cons

• costly
• contains soy

Best selenium multinutrient supplements

Selenium interacts with other nutrients such as vitamin E (24 ).

Many multinutrient formulas include selenium alongside vitamin E and other vitamins, minerals, and botanical extracts.

These multinutrient products can be useful for people who need broader nutrient support due to dietary limits, illness, or other conditions that increase nutrient demands.

Below are several recommended multinutrient supplements that include selenium.

Thorne Trace Minerals

• Price: $
• Dose: 1 capsule (100 mcg of selenium, or 182% of the DV)

Thorne is known for strong quality controls. The brand is certified by Australia’s Therapeutic Goods Administration (TGA), and its manufacturing site holds NSF certification (25).

Thorne Trace Minerals includes selenomethionine and a range of other minerals such as zinc, boron, chromium, manganese, and molybdenum.

Each capsule contains 100 mcg of selenium.

Pros

• TGA and NSF certifications
• provides various minerals
• reasonably priced

Cons

• not always stocked in local stores but available online

Vital Nutrients Multi-Nutrients (no iron or iodine)

• Price: $$$
• Dose: 3 capsules (100 mcg of selenium, or 182% of the DV)

Vital Nutrients is a well-regarded medical-grade brand. Their products undergo third-party lab testing for purity and potency.

The Multi-Nutrients formula (without iron or iodine) is a solid multivitamin choice covering most daily nutrient needs, including selenium — and omitting iron and iodine makes it suitable for people who don’t require those minerals.

Supplementing iron or iodine when not needed can be unnecessary or even harmful (26 , 27 ).

Three capsules provide 100 mcg of selenium.

Pros

• third-party tested
• omits iodine and iron

Cons

• expensive
• not suitable for those who need iron or iodine supplementation

Nordic Naturals Multi Minerals

• Price: $$$
• Dose: 3 capsules (41.25 mcg of selenium, or 75% of the DV)

Nordic Naturals Multi Minerals contains several minerals in absorbable forms, including 41.25 mcg of selenomethionine per serving, covering about 75% of the DV.

It also supplies other key minerals such as magnesium, zinc, and copper, making it a good choice for those needing additional mineral support.

The product is third-party tested, non-GMO verified, and certified vegan.

Pros

• third-party tested
• contains 11 essential minerals

Cons

• costly

A quick comparison

How to choose

When selecting a selenium supplement, remember that more isn’t always better. Excess selenium can be harmful, which is why the Tolerable Upper Intake Level for selenium is set at 400 mcg per day (3 ).

Although some research suggests higher doses may be tolerated in certain contexts, consult a qualified healthcare professional to determine your selenium needs before supplementing.

Doses of 5,000 mcg and above can cause toxicity and severe effects such as respiratory distress, heart attack, and kidney failure (28 ).

Most over-the-counter selenium supplements provide between 25 and 200 mcg per serving, which falls well below the upper limit.

When shopping, look for products that undergo independent testing for quality, and buy from reputable retailers or directly from manufacturers when possible.

Useful supplement shopping guides

Consider reading these articles to help you choose supplements wisely:

• How to Choose High Quality Vitamins and Supplements
• How to Read Supplement Labels Like a Pro

Frequently asked questions

What are the benefits of taking a selenium supplement?

Selenium supplementation may be useful for certain individuals, including those who don’t obtain enough from their diet or people with specific medical conditions.

For instance, strict vegetarians or vegans may be at risk for low selenium intake and could benefit from supplementation.

Selenium supplements have also been shown to help in some health conditions, like autoimmune thyroid disease (7 ).

Who should take a selenium supplement?

People at risk of deficiency — such as those on vegan diets and individuals with certain medical conditions like phenylketonuria, kidney failure, or HIV — may need selenium supplements (3 ).

Additionally, some people without deficiency, for example those with autoimmune thyroid disease, might benefit from supplementation (7 ).

What is the best type of selenium supplement?

Selenium as selenomethionine is often preferred. This form has shown better absorption compared with other supplemental forms like sodium selenite (3 , 8 , 9 ).

Are selenium supplements safe?

Generally, selenium supplements are safe when used appropriately. However, excessive intake can cause adverse effects, and most people don’t need very high doses.

Long-term excess selenium intake can produce symptoms such as garlic-like breath odor, metallic taste, hair loss, brittle nails, skin rashes, nausea, neurological changes, fatigue, diarrhea, mottled teeth, and irritability (3 ).

At toxic levels, selenium can cause severe outcomes like respiratory distress, heart attack, kidney failure, and even death. Toxicity often arises from consuming extremely high amounts, sometimes due to product mislabeling (3 ).

Who shouldn’t take selenium?

Most people who eat a varied diet including nuts, fish, meat, and eggs do not need selenium supplements.

Generally healthy individuals with adequate dietary intake should avoid high-dose selenium supplementation to prevent excessive intake and potential harm.

If you want to learn whether selenium supplementation is right for you, seek guidance from a qualified healthcare provider such as a physician or registered dietitian.

The bottom line

Your body needs only trace amounts of selenium, but ensuring adequate intake is important for overall health.

There are many quality selenium supplements available for those who need extra support.

Consult a healthcare professional to determine whether a selenium supplement is appropriate for you. If you choose to supplement, consider one of the products listed above to help ensure you’re using a reputable, high-quality option.