Best selenium supplement


Symptoms of selenium toxicity include nausea, stomach problems, and issues with the nervous system.

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Which selenium supplement is best?

Selenium is a trace mineral vital for thyroid function. It’s also thought to act as an antioxidant, which eliminates dangerous cancer-causing free radicals in the body. While it’s unlikely you’ll miss out on this nutrient if you’re eating a varied diet, a deficiency certainly requires supplementation.

Choosing a high-quality form of this mineral, like our top pick, the Thorne Research Selenomethionine 200 McGowen Selenium Supplement, is critical to ensure proper absorption. However, before beginning a supplementation routine of any kind, we recommend a visit with a doctor. Blood tests are the most accurate way to detect a deficiency and should be done before including supplements in your diet. There’s little point to adding selenium supplements to your pillbox if you don’t actually lack the nutrient. To learn more, keep reading our buying guide.

What to know before you buy a selenium supplement

Dietary needs

The majority of people consume enough selenium through their regular diets and don’t require supplements. However, there are a few individuals at risk for selenium deficiency:

  • People living in countries where selenium intake is low because of the type of diet available or the soil makeup in the area
  • Those who are HIV-positive
  • People receiving dialysis

Examples of foods that contain selenium are whole grains, milk, yogurt, fortified processed foods like cereal, and a variety of meats, including beef, chicken, and pork.

Daily recommended dose

Healthy adults require about 55 micrograms of selenium per day. Women who are pregnant or breastfeeding need a slightly higher amount, between 60 to 70 micrograms per day. Kids should not exceed 55 micrograms of selenium per day. It’s unnecessary to supplement in higher doses than recommended, and it may be unsafe if dosage amounts exceed 400 micrograms.

Organic vs. inorganic

Organic forms of selenium are higher quality and more easily absorbed by the human body. Examples of organic forms of selenium include:

  • selenocysteine
  • methylselenocysteine
  • selenomethionine

Inorganic types of selenium don’t stay in the body long enough to be adequately absorbed into the bloodstream.

Label information

Always check the label on the supplement bottle to verify whether the main ingredient is organic or not. Also check the label for other information. Added ingredients are not worth the cost. A high-quality selenium supplement shouldn’t have a long list of ingredients. Additional ingredients may pose a problem for individuals with allergies (e.g., yeast). Capsules made of gelatin aren’t suitable for vegetarians and vegans.


Did you know that selenium supplements tend to have strong scents? Read reviews before buying to find an option that emits less of an odor if you have any sensitivities.

What to look for in a quality selenium supplement

Serving size 

Consider how many capsules are required for supplementation. You may prefer to choose a supplement option that requires you to swallow fewer tablets.

Capsule size 

If you’re averse to swallowing pills, check that the capsules are not too large. Many bottles have an example of the capsule size pictured on the label for easy reference.

Third-party testing

For extra peace of mind, opt for a supplement that’s NSF-certified or SP-verified, which ensures the product has been tested for purity and potency.

How much you can expect to spend on a selenium supplement

You’ll pay between $5 and $20 for one bottle of selenium supplements. When deciding on which bottle offers the best value, check the serving size and number of pills included.

Selenium supplements FAQ

Q. Should I take a selenium supplement daily?

A. Talk to a doctor to figure out the best supplementation routine for your needs. If you eat a varied diet, it’s unlikely that you are selenium-deficient. A blood test is the only way to accurately diagnose a selenium deficiency.

Q. Is it safe to consume selenium supplements?

A. If taken in response to a diagnosed deficiency and according to manufacturer guidelines, selenium supplements are indeed safe. Do not take supplements of this type if you have not been formally diagnosed with a deficiency. Consuming too much may lead to selenium toxicity.

What selenium supplements are best to buy?

Top selenium supplement

Thorne Research Selenomethionine - 200 McGowen Selenium Supplement for Antioxidant Support

Thorne Research Selenomethionine – 200 McGowen Selenium Supplement for Antioxidant Support

Our take: A high-quality form of selenium that comes doctor-recommended.

What we like: The amino-acid bound supplement is readily aborted by the body and effective for treating deficiencies.

What we dislike: No reported side effects from consumers.

Where to buy: Sold at Amazon.

Top selenium supplement for the money

Nature’s Way Selenium 200 mcg – L-Selenomethionine

Nature’s Way Selenium 200 mcg – L-Selenomethionine

Our take: A budget selenium supplement well-liked by buyers.

What we like: Yeast-free formula is ideal for those with this type of food allergy. The body readily absorbs this form of selenium.

What we dislike: Pungent odor.

Where to buy: Sold at Amazon.

Worth checking out

MegaFood Selenium, Mineral Support for Immune Health Enhanced with Organic Foods and Botanicals

MegaFood Selenium, Mineral Support for Immune Health Enhanced with Organic Foods and Botanicals

Our take: A plant-based whole-food form of selenium.

What we like: Vegan-friendly and naturally derived. Does not upset the stomach.

What we dislike: Expensive, and a single pill contains a lower dosage than other brands.

Where to buy: Sold at Amazon.


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Steph Coelho writes for BestReviews. BestReviews has helped millions of consumers simplify their purchasing decisions, saving them time and money.

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