NEW
🧱 Boron
Cost per serving
$0.27
mineral · 6 active deals
The best-value Selenium right now is about $0.06 per dose — across 6 tracked products the median is $0.119/dose, so shopping on cost-per-dose can cut your cost several-fold. Every Selenium deal here is ranked by cost per dose— what you actually pay per serving, not the sticker price — because forms and absorption differ, so the cheapest bottle isn’t always the cheapest dose.
Right now the best value across our full Selenium catalog is at $0.06 per serving.
Recommended daily intake
Narrow safe range; one Brazil nut already covers the DV. General FDA/NIH adult guidance — not medical advice.
Selenium is an essential mineral that the body incorporates into 25 selenoproteins, including glutathione peroxidases, thioredoxin reductases, and selenoprotein P; per the NIH Office of Dietary Supplements, these selenoproteins play critical roles in thyroid hormone metabolism, DNA synthesis, reproduction, and protection from oxidative damage and infection. Because selenium has antioxidant properties and effects on DNA repair, apoptosis, and the endocrine and immune systems, it has been hypothesized to play a role in cancer prevention, but while some observational studies and one early trial suggested a lower risk (e.g., of prostate cancer), more recent randomized trials such as SELECT found that supplementation did not reduce cancer risk, and the NIH notes the evidence is limited and not conclusive. Selenium has also been studied in relation to cardiovascular disease, cognitive decline and Alzheimer's disease, HIV infection, male fertility, and thyroid disease, but the NIH states the evidence for these uses is generally limited, mixed, or insufficient to draw firm conclusions. In certain low-selenium regions, deficiency has been associated with conditions such as Keshan disease and Kashin-Beck disease, and it could exacerbate iodine deficiency, though deficiency is very rare in the United States — per the NIH Office of Dietary Supplements; not medical advice.
According to the fact sheet, the forms of selenium commonly found in dietary supplements include selenomethionine, selenium-enriched yeast (grown in a high-selenium medium, predominantly as selenomethionine), sodium selenite, and sodium selenate. The NIH states that the human body absorbs up to about 90% of the selenium from these forms. Selenium is available in multivitamin/mineral supplements (many containing 55 mcg), in combination products with vitamin E or other ingredients (generally 50 to 200 mcg), and as stand-alone selenium-only supplements (typically 100 to 400 mcg).
Because selenium is bound to protein in foods, high-protein foods tend to be the best sources: Brazil nuts, seafood, meat, poultry, and organ meats are the richest food sources, with Brazil nuts containing particularly high amounts (an average of about 544 mcg per ounce, though values vary widely). Other sources include cereals and other grains and dairy products, and the major dietary sources in the United States are breads, grains, meat, poultry, seafood, and eggs. Selenium levels in plant-based foods vary widely by geographic location because of differences in the amount and form of selenium in the soil — per the NIH Office of Dietary Supplements.
Every Selenium deal above is ranked by real cost per dose with no paid placement — see our and .
Independent third-party testing is a voluntary check of a product's identity, potency and contaminants by an outside lab. It's a quality signal, not a value or efficacy claim. Confirm any brand's current status on the official registries:
Testing status is self-reported by the brand or drawn from public certification and may change — always verify on the official registry before purchase.
The for adults age 19 and older is 55 mcg per day for both men and women. During pregnancy it is 60 mcg and during lactation 70 mcg. Across all ages, recommended intakes range from 15 to 70 mcg per day depending on age and life stage. — per the NIH Office of Dietary Supplements; general information, not medical advice.
Yes. The is 400 mcg per day for adults. Chronically high intakes cause selenosis: most commonly hair loss and nail brittleness or loss, plus garlic breath odor, metallic taste, skin rash, nausea, diarrhea, fatigue, irritability, and nervous system abnormalities. — per the NIH Office of Dietary Supplements; general information, not medical advice.
Selenium deficiency alone rarely causes overt illness, but it produces biochemical changes that may predispose people under additional stress to certain conditions, including Keshan disease (a cardiomyopathy) and Kashin-Beck disease (a type of osteoarthritis). It could also worsen iodine deficiency, potentially raising the risk of congenital hypothyroidism in infants. — per the NIH Office of Dietary Supplements; general information, not medical advice.
Deficiency is very rare in the United States, but groups most likely to have inadequate intakes include people living in selenium-deficient regions (such as parts of China with very low soil selenium), people undergoing kidney dialysis, and people living with HIV. — per the NIH Office of Dietary Supplements; general information, not medical advice.
We link primary sources and paraphrase their findings — never copy their text, tables, or images. Cost-per-dose figures are our own first-party catalog data.
Selenium deficiency is very rare in the United States and Canada, but groups at higher risk of inadequate intakes include people living in selenium-deficient regions (such as parts of China where soil selenium is very low), people undergoing kidney dialysis, and people living with HIV. On its own, selenium deficiency rarely causes overt illness, but it produces biochemical changes that may predispose people under additional stress to conditions such as Keshan disease (an endemic cardiomyopathy) and Kashin-Beck disease (a type of osteoarthritis), and it may exacerbate iodine deficiency, potentially increasing the risk of congenital hypothyroidism in infants — per the NIH Office of Dietary Supplements.
Selenosis results from chronically high selenium intakes and is most commonly characterized by hair loss and nail brittleness or loss, with other possible signs including a garlic odor in the breath, a metallic taste in the mouth, skin rash, nausea, diarrhea, fatigue, irritability, and nervous system abnormalities; acute toxicity from misformulated products can cause severe gastrointestinal, neurological, cardiac, and kidney effects and, rarely, death. The Tolerable Upper Intake Level (UL) for selenium is 400 mcg for adults, ranging from 45 mcg to 400 mcg for infants, children, and adolescents depending on age — per the NIH Office of Dietary Supplements.
Cost per serving
$0.27
Cost per serving
$0.15
Avg·−43%120 servings · ~120-day supply
Cost per serving
$0.33
Pricey90 servings · ~90-day supply
Cost per serving
$0.06
Cheap·−78%250 servings · ~250-day supply
Cost per serving
$0.06
Cheap·−78%240 servings · ~240-day supply
Cost per serving
$0.09
250 servings · ~250-day supply
Amazon.com · 🧱 Boron
CPS
Price
$24.00
SuperSmart USA LLC · SuperSmart · 🥦 Selenium
CPS
Price
$18.00
Amazon.com · 🥦 Selenium
CPS
Price
$29.99
Bronson · Amazon.com · 🥦 Selenium
CPS
Price
$14.99
Nutricost · Amazon.com · 🥦 Selenium
CPS
Price
$13.95
NOW Foods · Amazon.com · 🫁 NAC
CPS
Price
$21.85
Yes. Selenium supplements may interact with medications, and some medications can affect selenium levels. The example given is cisplatin, an inorganic platinum chemotherapy agent, which can reduce selenium levels in hair and serum, though whether these reductions are clinically significant is not known. — per the NIH Office of Dietary Supplements; general information, not medical advice.
Nutricost Selenium 200mcg at $0.06 per serving — the lowest cost-per-dose selenium in our catalog. See the full ranking on the Best Selenium page.
We're tracking 6 active Selenium deals across Amazon US and partner retailers, ranked by community votes and cost-per-dose — not paid placement.
Across 6 tracked Selenium deals the median cost-per-dose is $0.119; the cheapest quartile comes in under $0.067 per serving. Anything below the median is a solid deal for the same molecule.
Deals are submitted by the community and ranked by net votes (hot minus cold) plus cost-per-dose normalised across container sizes. We take no affiliate kickbacks for ordering; sponsored slots, when present, are clearly badged.
Selenosis results from chronically high selenium intakes and is most commonly characterized by hair loss and nail brittleness or loss, with other possible signs including a garlic odor in the breath, a metallic taste in the mouth, skin rash, nausea, diarrhea, fatigue, irritability, and nervous system abnormalities; acute toxicity from misformulated products can cause severe gastrointestinal, neurological, cardiac, and kidney effects and, rarely, death. The Tolerable Upper Intake Level (UL) for selenium is 400 mcg for adults, ranging from 45 mcg to 400 mcg for infants, children, and adolescents depending on age — per the NIH Office of Dietary Supplements.
Because selenium is bound to protein in foods, high-protein foods tend to be the best sources: Brazil nuts, seafood, meat, poultry, and organ meats are the richest food sources, with Brazil nuts containing particularly high amounts (an average of about 544 mcg per ounce, though values vary widely). Other sources include cereals and other grains and dairy products, and the major dietary sources in the United States are breads, grains, meat, poultry, seafood, and eggs. Selenium levels in plant-based foods vary widely by geographic location because of differences in the amount and form of selenium in the soil — per the NIH Office of Dietary Supplements.
Dosage, upper-limit, deficiency, food-source and interaction facts are sourced from the NIH Office of Dietary Supplements Selenium fact sheet. General information, not medical advice.
90 servings · ~90-day supply
