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Head-to-head evidence comparison — which supplement is right for you?
Selenium vs Zinc: Zinc has the stronger overall evidence (8.5 vs 6.5/10); they're alternatives for support immune system — the best pick depends on your goals. Take the 60-second quiz for a pick tailored to your goals.
Zinc wins 2 of 3 categories. Both are solid choices — the best pick depends on your specific goals.
Verdict
Likely helps
27 of 34 studies with measurable effects showed benefit.
Top outcomes
Verdict
Likely helps
21 of 26 studies with measurable effects showed benefit.
Top outcomes
Shared outcomes (1)
Outcomes where both Selenium and Zinc have evidence — compare verdict strength side-by-side.
100-200mcg
With food
Selenomethionine (best absorbed)
15-30mg daily
With meals
Zinc picolinate or zinc citrate
4-8 weeks
4-8 weeks
2-4 weeks
2-4 weeks
4-8 weeks
Immediate
Selenium, antioxidants, cardiovascular disease, and all-cause mortality: a systematic review and meta-analysis of randomized controlled trials
The American journal of clinical nutrition (2020) · Meta analysis · n=9423
However, a decreased risk with antioxidant mixtures was seen for CVD mortality when selenium was part of the mix (RR: 0.77; 95% CI: 0.62, 0.97; P = 0.02), with no association when selenium was absent.
Selenium for preventing cancer
The Cochrane database of systematic reviews (2018) · Meta analysis · n=27232
For analyses of RCTs with low risk of bias, the summary risk ratio (RR) for any cancer incidence was 1.01 (95% confidence interval (CI) 0.93 to 1.10; 3 studies, 19,475 participants; high-certainty evidence).
Selenium and prostate cancer: systematic review and meta-analysis
The American journal of clinical nutrition (2012) · Meta analysis · n=13254
Three high-quality studies included in the meta-analysis of toenail selenium and cancer risk indicated a reduction in prostate cancer risk (estimated RR: 0.29; 95% CI: 0.14, 0.61) with a toenail selenium concentration between 0.85 and 0.94 μg/g.
Efficacy of Zinc Supplementation in the Management of Primary Dysmenorrhea: A Systematic Review and Meta-Analysis
Nutrients (2024) · Meta analysis · n=739
Zinc supplementation significantly reduced pain severity compared to placebo (Hedges's g = -1.541; 95% CI: -2.268 to -0.814; p < 0.001), representing a clinically meaningful reduction in pain.
Effects of Daily Zinc Alone or in Combination with Other Nutrient Supplements on the Risk of Malaria Parasitaemia: A Systematic Review and Meta-Analysis of Randomised Controlled Trials
Nutrients (2023) · Meta analysis · n=1339
The effect sizes, represented as risk ratios (RRs) with 95% confidence intervals (CIs), were standardised by transforming them into log RRs and then pooling them using a fixed-effects or random-effects model depending on the heterogeneity across studies.
Prevalence of Zinc Deficiency in Inflammatory Bowel Disease: A Systematic Review and Meta-Analysis
Nutrients (2022) · Meta analysis · n=806
Pooled analyses by the IBD subgroup showed a total population of 1677 with CD, for an overall mean zinc deficiency prevalence of 54% and 95% confidence intervals (CI) ranging from 0.51 to 0.56, versus 41% (95%CI 0.38-0.45) in the UC population (n = 806).
Based on Cochrane systematic review showing moderate-certainty evidence for TPO antibody reduction. Effects on thyroid hormone levels (TSH, T4, T3) were inconsistent across studies.
Based on meta-analyses showing reduced respiratory tract infections and improved immune markers (CD3/CD4). Effects primarily in deficient individuals. Take with food to reduce nausea risk.
AI-estimated from published studies. Interpret as directional guidance.
Zinc has a higher evidence score (8.5/10 vs 6.5/10) and wins in 2 of 3 categories.
For support immune system, Zinc has a higher relevance score (90 vs 70).
No known interactions between Selenium and Zinc have been documented in our database. However, always consult a healthcare provider before combining supplements.
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The popular one (saw palmetto) mostly fails in rigorous trials; beta-sitosterol is the better bet.
The right pick depends on your goals. Answer a few quick questions for a personalised recommendation — or dig into the full evidence on each.