NOW Foods Selenium 200 mcg Review

NOW Foods Selenium 200 mcg is an essential trace mineral incorporated into selenoproteins, which are vital for antioxidant defense, thyroid hormone metabolism, and immune function.

Product Focus: Thyroid HealthAlso covers:HormonesImmune system

Tier ⓘ

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Members see this product's tier and why. Tiers run from 1, the strongest evidence, to 5. How we grade →

Evidence ⓘ

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How strongly the evidence says this product works: human studies count most, then real reviews, then our biohacker panel.

Positive Reviews

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Biohacker Mentions

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Study, Trial or Testing Result SummaryMembersHuman studies

This product gives 200 micrograms of selenium a day as selenomethionine, a dose that matches what thyroid studies used. The shows up mainly in people with autoimmune thyroid disease, such as Hashimoto thyroiditis. …

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Review Totals and SummaryMembers21,367 reviews

21,367 reviews · IHerb 21,268 · Walmart 60 · Naturitas 20 · Swanson 19

Reviews for NOW Foods Selenium 200 mcg are , with users expressing levels of and noting noticeable after incorporating the supplement into their daily routine. A number of reviewers from iHerb, Walmart, and other sites mention how easy the tablets are to swallow and appreciate their taste, which makes them convenient for regular use. …

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Biohacker SummaryMembersWhat our biohacker panel says

Nearly of the panel selenium, and eight of the nine who spoke about it gave a latest position of , while one was . The common reason is thyroid , especially the body convert thyroid hormone and supporting people with autoimmune thyroid , and others cite antioxidant and detox support, male fertility, hair , and immune . …

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RAL SummaryMembersThe tier and why

One review judged the evidence too for routine use. …

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More DetailsMembersBody systems · Combine with · Possible side effects

Body systems: Endocrine system, Immune system. Combine with and possible side are for members.

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Supplement FactsSelenium 200 mcg

Supplement Facts

Serving Size 1 Veg Capsule

Servings Per Container 180

Amount Per Serving% Daily Value

Selenium (elemental) (from 40 mg L-Selenomethionine)

200 mcg

364%

Directions: Take 1 capsule daily with a meal.

Barcode (UPC) 733739014863 · Label source: Swanson · Report a label change

Where to BuyNOW Foods · iHerb · Swanson

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Graded October 23, 2026 by the Reverse Age Lab evidence engine, from human studies, real reviews and our biohacker panel. How we grade. Is this medical advice? No. Rala organizes the published evidence; go over any change with your doctor, especially if you take meds.