We use essential cookies (authentication, your saved goals/stack) by default. With your permission we'll also enable privacy-respecting analytics (Vercel Web Analytics, anonymous load-time metrics) and error-replay diagnostics (Sentry — DOM snapshots only when an error fires) so we can fix bugs faster. Learn more
Head-to-head evidence comparison — which supplement is right for you?
Green Tea Extract and Selenium are closely matched across evidence, studies, and safety.
Verdict
Likely helps
7 of 9 studies with measurable effects showed benefit.
Top outcomes
Verdict
Likely helps
18 of 23 studies with measurable effects showed benefit.
Top outcomes
Shared outcomes (1)
Outcomes where both Green Tea Extract and Selenium have evidence — compare verdict strength side-by-side.
250-500mg EGCG (or 500-1000mg green tea extract)
With meals, Morning or pre-exercise
Standardized extract (45-50% EGCG)
100-200mcg
With food
Selenomethionine (best absorbed)
Acute and 4-8 weeks
Acute
30-60 minutes
4-8 weeks
4-8 weeks
Green tea (Camellia sinensis) for the prevention of cancer
The Cochrane database of systematic reviews (2020) · Meta analysis · n=1795
For incident prostate cancer, the summary risk ratio (RR) in the green tea-supplemented participants was 0.50 (95% confidence interval (CI) 0.18 to 1.36), based on three studies and involving 201 participants (low-certainty evidence).
Impact of flavan-3-ols on blood pressure and endothelial function in diverse populations: a systematic review and meta-analysis of randomized controlled trials
European journal of preventive cardiology (2025) · Meta analysis · n=5205
Flavan-3-ol interventions included epicatechin, epigallocatechin-gallate, cocoa products, tea, grape extract, and apples delivering 586 mg (95% CI 510, 662) total flavan-3-ols.
The effects of green tea extract supplementation on body composition, obesity-related hormones and oxidative stress markers: a grade-assessed systematic review and dose-response meta-analysis of randomised controlled trials
The British journal of nutrition (2024) · Meta analysis · n=3802
Pooled effect sizes indicated that BM, BFP, BMI and MDA significantly reduced following GTE supplementation.
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.
Based on meta-analysis showing 9.29 mg/dl LDL reduction with 107-856 mg/d EGCG. Optimal cardiovascular benefits observed at 400-500 mg/day. Take with food to reduce GI side effects.
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.
AI-estimated from published studies. Interpret as directional guidance.
Both Green Tea Extract and Selenium are closely matched — the best choice depends on your specific health goals.
For reduce inflammation, Green Tea Extract has a higher relevance score (85 vs 52).
No known interactions between Green Tea Extract and Selenium have been documented in our database. However, always consult a healthcare provider before combining supplements.