The 10 Best Selenium Supplements, According to a Dietitian

• 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

The brands that made this list are trusted by healthcare professionals and set strict standards for the quality and safety of their supplements.

The supplements on this list contain selenium in the form of selenomethionine, which has been shown to have superior absorption rates to other forms of selenium used in supplements, including sodium selenite (3, 8, 9).

When shopping for supplements, it’s important to purchase high quality products from brands that healthcare professionals trust.

This article examines selenium supplements based on the following criteria:

• Quality. The selenium supplements are tested for quality and purity, ideally by a third-party organization.
• Selenium type. The supplements contain selenomethionine for better absorption.
• Dose. The supplements contain an effective dose of selenium.
• Price. We included products to suit a variety of budgets.
• Vetting. All the products included have been vetted to ensure that they meet Healthline’s medical and business standards.

Selenium is most commonly sold in capsule form. Here are some of the best selenium capsules on the market.

Klaire Labs Seleno Met

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

Klaire Labs is a trusted supplement brand that manufactures professional-grade nutrition supplements in compliance with the FDA’s current good manufacturing practices (CGMPs).

CGMP regulations require that supplement manufacturers take steps to ensure their products are safe and effective.

Seleno Met contains selenium in the form of L-selenomethionine‚ which has been shown to have superior absorption compared with other forms of selenium commonly found in supplements (3, 8, 9).

Seleno Met is free of common allergens like casein, shellfish‚ tree nuts‚ gluten‚ soybeans‚ and corn and contains no artificial flavors, colors‚ or preservatives.

One capsule delivers 200 mcg of selenium.

Pure Encapsulations Selenomethionine

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

Many healthcare professionals use Pure Encapsulations products. The company exceeds the standard for United States Pharmacopeia (USP) supplement manufacturing and follows CGMP manufacturing procedures (10).

The company also independently tests its products for potency, contaminants, and allergens. Additionally, it’s certified gluten-free and free of genetically modified organisms (GMOs) (10).

One capsule delivers 200 mcg of selenium.

NOW Foods Selenium (yeast-free)

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

NOW Foods is a supplement company that offers high quality dietary supplements. NOW Foods selenium can be found in most natural foods stores and some larger grocery store chains.

The brand exceeds the FDA’s CGMPs for the dietary supplement industry and is certified non-GMO.

What’s more, NOW is certified by Underwriters Laboratories (UL), a third-party testing organization that ensures companies meet strict standards for supplement manufacturing.

Now Foods Selenium (yeast-free) supplement contains the highly absorbable L-selenomethionine and is free from common allergens like gluten and soy.

One capsule delivers 200 mcg of selenium.

Bluebonnet Selenium

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

Bluebonnet is another supplement brand that can be found in many grocery and specialty stores.

Bluebonnet is NSF GMP-registered, meaning that NSF ensures the company meets GMP requirements for manufacturing, including label claims regarding composition, identity, quality, and purity.

Bluebonnet is also kosher and certified vegan, soy-free, and gluten-free. Bluebonnet Selenium contains selenomethionine for optimal absorption.

One capsule delivers 200 mcg of selenium.

Selenium is essential for the health and functioning of your immune system (11).

Many supplements used to support immune function contain selenium along with other important nutrients for immune health, including vitamin C and zinc (12).

Here are some of the best selenium supplements for immune support.

NOW Foods EpiCor Plus Immunity

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

NOW Foods EpiCor Plus Immunity supplement contains a potent combination of selenium, vitamin D3, zinc, and vitamin C — all of which are necessary for proper immune system function.

The supplement also contains an ingredient called EpiCor, which is derived from the yeast Saccharomyces cerevisiae.

EpiCor has been shown to reduce inflammation and support the body’s immune response in some small, limited research studies sponsored by Embria Health Sciences, the creator of EpiCor (13, 14).

Both studies had limitations, including a very small sample size, and some testing was conducted on animals instead of humans. Thus, further research will be needed to better understand EpiCor and its role in human immune health.

Carlson Labs ACES + Zinc

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

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

All these nutrients are necessary for the proper functioning of the immune system (12).

For people who need extra nutrient support, this supplement may be a decent option. However, it may not be appropriate for everyone.

It contains a large amount of vitamin E — more than 1,000% of the DV. And some studies suggest that long-term supplementation with high doses of vitamin E may increase the risk of prostate cancer in healthy men (15).

For this reason, men who have prostate cancer or have a family history of it should check with a healthcare professional to find out whether this supplement is safe and appropriate for them.

Carlson’s website mentions that their supplements are tested by an FDA-registered laboratory for potency and quality. However, the website does not disclose whether their supplements are tested by a third party.

Supplementing with selenium has been associated with improved prostate health in some studies and may help protect against prostate cancer in men with low blood levels of selenium (16, 17).

However, other studies have noted an association between selenium supplements and high grade prostate cancer or found no benefit of selenium in reducing prostate cancer risk (18).

It’s likely that selenium supplements have varying effects on prostate health based on blood selenium levels, genetics, and other factors and may be beneficial for only certain people.

If you’re interested in taking selenium for prostate health or prostate cancer prevention, it’s important to consult a healthcare professional to make sure a supplement is safe for you.

Pure Encapsulations SP Ultimate

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

Pure Encapsulation SP Ultimate is meant to support the health of the male reproductive system.

It combines selenium in the form of Selenomax (yeast-bound L-selenomethionine) with saw palmetto, zinc, lycopene, curcumin, green tea extract, and other ingredients that may benefit prostate health (19, 20, 21, 22, 23).

Three capsules deliver 70 mcg of selenium, or 100% of the DV.

Selenium works together with other nutrients, including vitamin E (24).

Many multinutrient supplements contain selenium and vitamin E, as well as other vitamins, minerals, and plant compounds.

These supplements may be a good choice for people who need extra support because of dietary restrictions, illness, or other medical conditions that increase nutrient needs.

Here are some of the best multinutrient supplements that contain selenium.

Thorne Trace Minerals

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

Thorne is a supplement company that takes quality seriously. Thorne is certified by the Therapeutic Goods Association (TGA), a regulatory agency run by the Australian Government Department of Health. Plus, their production facility is certified by NSF International (25).

Thorne Trace Minerals contains selenomethionine and other minerals, including zinc, boron, chromium, manganese, and molybdenum.

One capsule delivers 100 mcg of selenium.

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 trusted brand in the medical field, and for good reason. It produces high quality nutritional supplements that undergo third-party laboratory testing to ensure quality and purity.

Vital Nutrients Multi-Nutrients with no iron or iodine is a great choice for a multivitamin that covers your daily needs for most nutrients, including selenium. And because it doesn’t contain iron or iodine, it’s a good option for people who don’t need to supplement with those minerals.

Although supplementing with iodine and iron is recommended for those with nutrient deficiencies, it’s unnecessary for people with adequate levels and can even be harmful (26, 27).

Three capsules deliver 100 mcg of selenium.

Nordic Naturals Multi Minerals

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

Nordic Naturals Multi Minerals contains a variety of minerals in highly absorbable forms, including 41.25 mcg of selenomethionine, which covers 75% of the DV for this nutrient.

It also provides 10 other essential nutrients, including magnesium, zinc, copper, and other minerals in bioavailable forms, making it an excellent choice for those who need additional nutrients in their diet.

This supplement is third-party tested, non-GMO verified, and certified vegan.

When searching for a selenium supplement, it’s important to understand that more isn’t necessarily better. In fact, taking too much selenium can be dangerous, which is why a Tolerable Upper Intake Level of 400 mcg per day has been set for selenium intake (3).

Although research shows that higher doses can be safely tolerated, it’s important to consult a qualified healthcare professional to assess your selenium needs before supplementing with selenium.

Doses of 5,000 mcg and higher can cause toxicity and lead to respiratory distress, heart attack, and kidney failure (28).

Most selenium supplements contain between 25 and 200 mcg of selenium per serving — well under the set upper limit.

When shopping for a selenium supplement, look for products that undergo independent testing for quality and try to purchase supplements from trusted sites or directly from the manufacturer whenever possible.

What are the benefits of taking a selenium supplement?

Taking supplemental selenium may be helpful for certain people, including those who don’t get enough selenium in their diet and those with certain medical conditions.

For example, those following a vegan or strict vegetarian diet may be at risk of developing a selenium deficiency and may benefit from supplemental selenium.

Selenium supplements may also benefit those with certain health conditions, including autoimmune thyroid disease (7).

Who should take a selenium supplement?

People who are at risk of a selenium deficiency — such as those following vegan diets and those with certain medical conditions, including phenylketonuria, kidney failure, and HIV — should take a selenium supplement (3).

Additionally, selenium supplements may be helpful for some people who are not deficient in selenium, including those with autoimmune thyroid disease (7).

What is the best type of selenium supplement?

Selenium in the form of selenomethionine may be the best option. This form has been shown to have superior absorption rates compared with other forms of selenium used in supplements, including sodium selenite (3, 8, 9).

Are selenium supplements safe?

Yes, selenium supplements are generally safe. However, it’s possible to take too much, which can lead to side effects. Also, most people do not need to supplement with high doses of selenium.

If you take too much selenium over a long period of time, it can lead to symptoms such as breath that smells like garlic, a metallic taste in your mouth, hair loss, brittle nails, skin rashes, nausea, nervous system abnormalities, fatigue, diarrhea, mottled teeth, and irritability (3).

If selenium reaches toxic levels in your body, it can lead to dangerous symptoms like respiratory distress syndrome, heart attack, kidney failure, and heart failure. It can even lead to death.

Keep in mind that selenium toxicity is usually caused by people taking excessively high amounts of selenium as a result of product mislabeling (3).

Who shouldn’t take selenium?

Most people don’t need to supplement with selenium because the nutrient is present in many foods, including nuts, fish, meat, and eggs.

Generally healthy people who consume a well-rounded diet should not supplement with high doses of selenium, as this can lead to excessive selenium intake, which can harm health.

If you’re interested in learning more about selenium and whether a selenium supplement may be appropriate for your health needs, get advice from a qualified healthcare professional such as a doctor or registered dietitian.

Although your body needs only small amounts of selenium to function at its best, making sure you get enough of this nutrient is essential for overall health.

Many excellent selenium supplements are available to consumers who may need an extra boost of this important mineral.

You can consult a healthcare professional to find out whether taking a selenium supplement is the right choice for your health. If you opt to take a supplement, you may want to choose one of those listed above to ensure you’re taking a high quality product.