Research Radartracking 1,138 published studies · 277 human · 6 safety signals · 42 clinical trials · 44 cancer pages · updated Jul 2026Open the Research Map →

Selenium (Stand-alone)

Trace element: GPx/TrxR ↑, p53 apoptosis ↑; moderate deficiency-correction in prostate/lung/colorectal/breast.

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Human-reviewed · How we review →

AI extractedhuman reviewedsources checkedretractions suppressed

Evidence at a glanceHuman · observationalMixed results⚠ Studies disagree
2 published studies tagged to this agent1 human studies approved & graded (trial, observational, or meta-analysis)
Why this grade?

Human · observational — Human observational evidence only — no trials.

  • 1 human · 0 animal · 0 lab · 1 review/other
  • Most authoritative study: Dietary Factors Modulating Colorectal Carcinogenesis
  • Studies disagree on the reported direction (conflict flagged).
  • Findings conflict across studies
  • Effect sizes reported in only 1 of 2 studies

Computed deterministically from the studies’ types and reported outcomes — not written by AI, and not a claim that anything works.

🏥⭐⭐⭐ Moderate — Mixed clinical data: correcting deficiency shows the clearest benefit; prevention trials in selenium-replete populations are neutral/negative. Prefer status-guided, form-specific use.SeSelenomethionineMethylselenocysteine

Forms: Selenomethionine capsules (200 mcg) · Sodium selenite tablets

Educational only, not medical advice. OncoForge makes no claim that Selenium (Stand-alone) treats, prevents, or cures any condition, beyond what the linked studies show. Evidence levels vary; effects may not translate to people, and some compounds can cause harm. Always coordinate with your oncology team.

Key Takeaway

Cofactor for selenoenzymes (GPx, TrxR) that buffers redox stress; certain selenium metabolites (e.g., methylselenol) can push p53-mediated apoptosis. Clinical signals are context-dependent—benefit is more likely when correcting deficiency; indiscriminate high-dose use can be harmful.

Evidence at a glance

Tier 3 · early humanProstateLungColorectalBreast

SELECT/NPC mixed prevention; adjunct RCTs modest (HR 0.8-1.0); strongest in low-Se baseline; meta-GPx ↑20-30%; ongoing platino-tox trials.

How it may work

Selenium incorporates into glutathione peroxidases (GPx) and thioredoxin reductases (TrxR), lowering peroxides and stabilizing redox signaling. Pro-apoptotic selenium metabolites (methylselenol) enhance p53 transactivation, DNA damage responses, and caspase cleavage, selectively stressing tumor cells with impaired antioxidant reserve. In adjunct settings, selenium may reduce chemo/radiotoxicity and modulate immunity; prevention data are mixed and strongly moderated by baseline selenium status and chemical form.

Targets & pathways

Curated mechanistic targets reported for this agent — how it may act on cells, not proof of a clinical effect.

  • GPx↑Peroxide detoxification
  • TrxR↑Redox signaling stabilization
  • p53 Apoptosis↑Methylselenol-mediated activation
  • DNA Repair↑Selenoprotein support
  • ImmunityModT-cell function enhancement
GPxTrxRp53 Apoptosis

Often studied / combined with

Combinations reported in the literature, not a protocol or a recommendation.

Overlapping mechanisms

Safety & interactions

Severity and how well-established each signal is are shown separately. Verify everything with your oncologist or pharmacist — absence here does not mean safe.

Risk categories
SelenosisDeficiency WorsenVitamin E Interaction
Potential interactions
  • platinum_chemoMonitorLowTheoreticalPotential antagonism; time separately.
  • antioxidantsSynergizeLowTheoreticalRedox balance enhancement.
  • CisplatinSynergizeLowTheoreticalNephroprotection in lung cancer.

Timing

References

Research

Where the evidence is

What has been studied, and how strong it is, by topic. A dashed cell means no studies were found for that combination — a gap, not evidence of no effect. Open a row to see its studies.

CancerHuman evidenceMechanismSafetyTrial
Squamous Cell Carcinoma Of The Cervix11——
Colonic Neoplasms—1——
Colorectal Cancer—1——

Reported figures

What supports this page

The kinds of sources behind this page, strongest at the top. Faint rungs show what is not here yet.

Guideline
0
Meta-analysis
0
Systematic review
0
Randomized trial
0
Clinical trial
0
Observational
1
Case report
0
Review
1
Preclinical
0
Other
0
2 studies1 human1 review/other

Tracking 2 published studies of Selenium (Stand-alone): 1 in humans, 1 reviews/other.

Reported direction across studies: 1 positive, 1 mixed.

Findings conflict — both supportive and negative/mixed results exist (see below). Human evidence is limited.

These counts summarize what the studies reported; they are not a measure of whether Selenium (Stand-alone) works.

Cancers named in these studies

colorectal cancer (1)colonic neoplasms (1)squamous cell carcinoma of the cervix (1)

Conflicting evidence

All studies

ReviewMixed resultsLimited evidenceTier 4 · clinical

Dietary Factors Modulating Colorectal Carcinogenesis

Nutrients · Jan 2021 · review

Seleniumcolorectal cancercolonic neoplasms

This is a narrative review summarizing recent evidence on how diet influences colorectal cancer risk. The authors state that a Western diet (high in fat, red and processed meat) is associated with increased risk, whereas higher dietary fiber and some micronutrients (vitamin D, selenium, calcium, antioxidants) may have protective effects; diet-induced changes in the gut microbiota can either increase or decrease risk.

Key findings
  • Western diet characterized by high fat, red meat and processed meat intake is an important contributor to colorectal cancer risk.
  • High intake of dietary fiber may partially counteract the unfavorable effects of meat via reduced intestinal transit time, dilution of carcinogens, antioxidant provision, and increased production of protective fermentation products such as butyrate.
  • Some micronutrients (vitamin D, selenium, calcium, vitamins C and E) have been advocated to have protective effects against colorectal cancer.
  • Diet-induced modifications of the gut microbiota modulate colonic epithelial homeostasis and can produce either mutagenic/carcinogenic agents or protective compounds.
  • Modification of diet and lifestyle may modify colorectal cancer risk and, per the authors' statement, could prevent neoplasia in up to 50% of cases.
Limitations: This is a review article that does not present new primary data or original trial results.; The review summary includes broad prevention estimates (e.g., "up to 50%" prevented) that are not quantified here and may reflect underlying heterogeneity in the literature.; Dietary and microbiome effects are described as having opposing effects under different conditions, indicating complexity and potential heterogeneity across studies..

AI summary of the abstract, human-reviewed · Jul 2026. Describes what this study reported, not medical advice. View on PubMed · Full text

Human · observationalMechanismReported positiveLimited evidenceTier 3 · early humann = 103

Correlations between serum progesterone and smoking, and the growth fraction of cervical squamous cell carcinoma

Anticancer research · Sep 2000 · observational (cross-sectional) analysis of 103 cases

Seleniumsquamous cell carcinoma of the cervix

Researchers measured tumor DNA S-phase fraction (SPF) as a marker of growth in 103 cases of invasive squamous cervical cancer and compared SPF (<14% vs ≥14%) with DNA ploidy, serum progesterone, serum estradiol, smoking and clinical/pathological factors. They report that aneuploidy, serum progesterone ≥2.6 nmol/l, and smoking were significantly associated with higher SPF (≥14%) after adjustment, with the progesterone and smoking associations driven by premenopausal women. The authors conclude increased tumor growth was associated with higher serum progesterone, smoking and aneuploidy in these patients.

Reported effects: Aneuploidy (OR) 10 · serum progesterone ≥2.6 nmol/l (OR) 7.5 · +1 more

Studied with: smoking.

Key findings
  • Sample: 103 cases of squamous cervical cancer stage IB-IV; tumor growth measured by DNA S-phase fraction (SPF), dichotomized at 14%.
  • Aneuploidy was significantly associated with SPF ≥14% (odds ratio (OR) 10.0).
  • Serum progesterone ≥2.6 nmol/l was significantly associated with SPF ≥14% (OR 7.5).
  • Smoking was significantly associated with SPF ≥14% (OR 3.0).
  • The associations of serum progesterone and smoking with higher SPF were attributed to an increased risk among premenopausal women.
Limitations: Observational cross-sectional design — cannot establish causation, only association.; Abstract provides limited detail on adjustment covariates and analytic methods.; Timing of serum hormone measurements relative to menstrual cycle or treatment is not reported in the abstract.; Single-cohort sample of 103 patients; generalizability and potential for residual confounding not addressed in abstract..

AI summary of the abstract, human-reviewed · Jun 2026. Describes what this study reported, not medical advice. View on PubMed

What changed recently

The latest additions to Selenium (Stand-alone)'s evidence base, and anything that's been retracted.

Recently added

Cancers where Selenium (Stand-alone) reported positive results

Where at least one study reported a positive result, shown with the full picture, not just the wins. Positive results are more likely to be published, and most of these are early lab or animal studies that may not translate to people. This reports what studies found, not what works.

Human evidence

Squamous cell carcinoma of the cervix1 positive1 human
Limitations: Observational cross-sectional design — cannot establish causation, only association.; Abstract provides limited detail on adjustment covariates and analytic methods.; Timing of serum hormone measurements relative to menstrual cycle or treatment is not reported in the abstract.; Single-cohort sample of 103 patients; generalizability and potential for residual confounding not addressed in abstract..
Cited positive studies (1)

Evidence at a glance: Selenium (Stand-alone) by cancer

A deterministic grade of what published studies report for each: strength of evidence, the reported direction, and the largest credible effect, strongest-evidence first. This summarizes findings; it is not a claim that anything works.

Squamous cell carcinoma of the cervixHuman · observationalReported positive1 human

Human observational evidence only — no trials.

Largest credible effect: Aneuploidy (OR) 10 PMID 11268431 · odds ratios 3–10 across 3 studies

Most authoritative study: Correlations between serum progesterone and smoking, and the growth fraction of cervical squamous cell carcinoma

Based on a single study.
Colonic neoplasmsInsufficient evidenceMixed results

No primary experimental studies yet.

Most authoritative study: Dietary Factors Modulating Colorectal Carcinogenesis

No human studies yet · No numeric effect sizes reported · Based on a single study.
Colorectal cancerInsufficient evidenceMixed results

No primary experimental studies yet.

Most authoritative study: Dietary Factors Modulating Colorectal Carcinogenesis

No human studies yet · No numeric effect sizes reported · Based on a single study.

Dose: as studied, not a recommendation

These are doses as studied or reported, never a recommendation. The right amount of Selenium (Stand-alone) depends on you, your other medicines, and your situation; decide it with your oncology team and pharmacist, not from a web page.

Ranges seen in adjunct / practice use: 55–200 mcg/day (po) With meals; status-guided, RDA 55 mcg (women)/70 mcg (men); adjunct 100-200 mcg/day; upper safe 400 mcg; test serum Se 70-150 mcg/L target..

Clinical trials studying Selenium (Stand alone)

0 ongoing · 0 completed · tracked from ClinicalTrials.gov. Recruiting is not the same as proven, and completed is not the same as positive — read the results. Not a recommendation.

2 stopped (terminated / withdrawn / suspended)

Search all trials on ClinicalTrials.gov →

Appears in these protocol claims

Selenium (Stand-alone) is named in these protocols discussed online. Listed for transparency: being part of a protocol is not evidence that it works, and OncoForge does not endorse them.

Inclusion here is not an endorsement. OncoForge makes no claim beyond what the linked studies show. Discuss anything on this page with your oncology team before acting on it.

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