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Head-to-head evidence comparison — which supplement is right for you?
Iron wins 1 of 3 categories. Both are solid choices — the best pick depends on your specific goals.
Verdict
Likely helps
7 of 9 studies with measurable effects showed benefit.
Top outcomes
Verdict
Probably helps
9 of 13 studies with measurable effects showed benefit.
Top outcomes
Shared outcomes (1)
Outcomes where both Green Tea Extract and Iron 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)
18-45mg elemental iron for deficiency (varies by severity)
On empty stomach if tolerated, Away from tea, coffee, dairy
Ferrous bisglycinate (gentle, well-absorbed) or iron protein succinylate
Green tea reduces iron absorption by 60-70%
Separate by 1+ hour. Take iron between meals, green tea with meals.
Acute and 4-8 weeks
Acute
30-60 minutes
2-4 weeks
4-8 weeks
4-12 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.
Daily oral iron supplementation during pregnancy
The Cochrane database of systematic reviews (2024) · Meta analysis · n=48971
There is probably little to no difference in maternal death (2 versus 4 events, RR 0.57, 95% CI 0.12 to 2.69; 3 trials, 14,060 women; moderate-certainty evidence).
The Prevalence of Anemia among Pregnant Women in China: A Systematic Review and Meta-Analysis
Nutrients (2024) · Meta analysis · n=722
The results showed that the prevalence of anemia, ID, and IDA among pregnant women in China were 30.7% (95% CI: 26.6%, 34.7%), 45.6% (95% CI: 37.0%, 54.2%), and 17.3% (95% CI: 13.9%, 20.7%), respectively.
Treatment for women with postpartum iron deficiency anaemia
The Cochrane database of systematic reviews (2024) · Meta analysis · n=572
Intravenous iron versus oral iron supplementation The evidence is very uncertain about the effect of intravenous iron on mortality (risk ratio (RR) 2.95, 95% confidence interval (CI) 0.12 to 71.96; P = 0.51; I² = not applicable; 3 RCTs; 1 event; 572 women; very low-certainty evidence).
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 meta-analyses showing hemoglobin improvements of 2.01-5.30 g/dL in iron deficient populations. Higher doses show diminishing returns with increased GI side effects. Effectiveness varies significantly by baseline iron status and form used.
AI-estimated from published studies. Interpret as directional guidance.
Iron has a higher evidence score (9/10 vs 9/10) and wins in 1 of 3 categories.
For boost daily energy, Iron has a higher relevance score (90 vs 58).
Green tea reduces iron absorption by 60-70% Separate by 1+ hour. Take iron between meals, green tea with meals. Consult a healthcare provider for personalized advice.