Compound Profile
Selenium
No consistent benefit in cancer prevention; essential for deficiency.
Last reviewed: •2 sources citedReport a correctionProfile-wide ·A Strong
Use extra caution — High doses toxic (selenosis). Details
- Evidence
- Strong evidence
- Typical onset
- Varies by prep
- Safety rating
- Use extra caution: Use caution
- Best for
- Selenoproteins, Glutathione Peroxidase, Thyroid Hormone Metabolism
- Avoid / review if
- Avoid Excessive Supplementation.
Safety
Safety & Cautions
High doses toxic (selenosis).
High caution
Caution level: High. Multiple caution categories apply, or the record uses avoid/contraindication language.
Evidence Summary
Profile-wide ·A StrongEvidence lens
Most useful for practical interpretation when safety context also fits.
StrongStrong evidence
Human clinical evidence: Present in source signals
Mechanistic / preclinical: Mechanism mapped — Metabolic Regulation · Selenoprotein Dependent Antioxidant Defense · Oxidative Stress Modulation
Research maturity: Established research — main contexts: Selenoproteins · Glutathione Peroxidase · Thyroid Hormone Metabolism
Safety boundary: Safety note available — High doses toxic (selenosis).
This profile cites 2 human studies.
Evidence Strength
Confidence estimate based on the design quality and consistency of published clinical trials.
Selenium has a strong evidence rating.
AdaptogenStress & MoodLongevity
Citation density
1.0
Sources
3
Effects
3
Research recency
Mixed recency
Evidence Grade
Grade A: Strong Evidence
Evaluation of methodological rigor, population reach, and evidence alignment.
- Design Match
- Meta analysis
- Risk of Bias
- Low
- Consistency
- Consistent
Strongest recorded design is a meta analysis, drawn from 5 recorded studies, 3 in people. No disagreement is recorded across them.
How evidence grades work
Each grade reflects the strength and consistency of published human evidence — not marketing claims. Grades are based on study count, design quality, effect size, consistency, and recency.
- Strong
- Multiple RCTs, consistent direction, adequate effect size
- Moderate
- Some RCTs or consistent observational data in humans
- Preliminary / Mixed
- Animal or in-vitro only, or conflicting human data
- Traditional / Theoretical
- Traditional use only; no controlled human trials
Clinical Study Summaries (3)2 human evidence sources · 0 human trials · Participant totals not consistently reported · Consistency not yet classifiable
Filter by study class
Showing 3 of 3 studies.
What the evidence actually shows
This table contains 3 structured sources, including 2 human evidence sources; 0 are human trials.
| Study | Design | N | Dose | Duration | Population | Outcome | Result & magnitude | Source |
|---|---|---|---|---|---|---|---|---|
PubMed · Am J Clin Nutr · 2003 Background | Meta-analysis Statistically combines results from multiple eligible studies; confidence still depends on the quality, consistency, and directness of those studies. | — | — | — | — | — | — | PubMed → |
Background | Meta-analysis Statistically combines results from multiple eligible studies; confidence still depends on the quality, consistency, and directness of those studies. | — | — | — | — | — | A five-trial synthesis in Graves orbitopathy reported improvement in clinical activity score, while quality-of-life and visual-function outcomes were not significantly improved. The signal is disease-specific and should not become a general thyroid or eye-health claim. | PubMed → |
Apoptosis by dietary agents for prevention and treatment of prostate cancer PubMed · Endocr Relat Cancer · 2010 Background | Narrative review Summarizes selected literature without the full prespecified search and selection methods of a systematic review. | — | — | — | — | — | — | PubMed → |
How Selenium Works
Simplified mechanism pathway based on preclinical and pharmacological evidence. Does not confirm clinical efficacy.
Mechanism Pathway — How Selenium Works
CompoundTarget / ReceptorMechanismEffect / Outcome
Dosing
- Common form
- chelated mineral capsule or powder
- No standardized dose
- Our source data records the usual product form for this ingredient but no studied dose. Preparations differ widely, so follow the standardization on the product you actually have and speak to a clinician before starting.
Mechanisms & biological pathways
Preclinical mechanism details from scientific profiles; these represent plausible pathways but do not guarantee clinical efficacy in humans.
- Metabolic Regulation
- Selenoprotein Dependent Antioxidant Defense
- Oxidative Stress Modulation
- Hormonal Signaling Context
- Immune Function Support
- Thyroid Hormone Metabolism Modulation
Compare & Sourcing
Compare side-by-side tradeoffs or verify active marker guidelines.
Review available sources for Selenium
Independent database mapping — evaluated separately from safety and efficacy scores.
Affiliate disclosure: Shopping links may earn this site a commission at no cost to you. Links are chosen on quality and availability, never commission tiers; safety warnings and evidence ratings stay independent.
Safety first · Harm reduction
This information is educational and not medical advice. Start low, avoid risky combinations, and consult a licensed clinician before making health decisions—especially if you use medications, have diagnosed conditions, or are pregnant/breastfeeding.
Learn how we evaluate confidence, safety, and intensity on the methodology page.
Founder & Head Researcher · Oak Ridge, TN · Last reviewed August 2026
Editorial Review
Checked against primary sources, cited evidence, and contraindication language before publication. Evidence claims, safety language, and affiliate modules are reviewed independently. Not personal medical advice.
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