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Head-to-head evidence comparison — which supplement is right for you?
Citrulline Malate vs Iron: Iron has the stronger overall evidence (9 vs 6/10); they're alternatives for boost daily energy — the best pick depends on your goals. Take the 60-second quiz for a pick tailored to your goals.
Iron wins 2 of 3 categories. Both are solid choices — the best pick depends on your specific goals.
Verdict
Probably helps
2 of 3 studies with measurable effects showed benefit.
Top outcomes
Verdict
Likely helps
6 of 8 studies with measurable effects showed benefit.
Top outcomes
6-8g citrulline malate pre-workout
30-60 minutes before exercise, Empty stomach or with light carbs
Citrulline Malate 2:1 powder
18-40mg elemental iron for deficiency (varies by severity) (a typical label dose, not the dose used in the cited trials, which used 60 to 120 mg a day)
On empty stomach if tolerated, Away from tea, coffee, dairy
Ferrous bisglycinate (gentle, well-absorbed) or iron protein succinylate
and 6 more not shown
Acute (within session)
Acute
24-48 hours
Acute
2-4 weeks
4-8 weeks
4-12 weeks
Acute Effect of Citrulline Malate on Repetition Performance During Strength Training: A Systematic Review and Meta-Analysis
International Journal of Sport Nutrition and Exercise Metabolism (2021) · Meta analysis · n=137
Meta-analysis of 8 double-blind placebo-controlled studies with 137 participants, most of them strength-trained men.
Impact of Chronic Nitrate and Citrulline Malate Supplementation on Performance and Recovery in Spanish Professional Female Soccer Players: A Randomized Controlled Trial
Nutrients (2025) · Rct · n=34
Plasma NO3- concentrations significantly increased from baseline in the NIT + CM group and remained elevated 24 h after the final dose, confirming sustained systemic exposure.
Effects of Acute Citrulline Malate Supplementation on CrossFit(®) Exercise Performance: A Randomized, Double-Blind, Placebo-Controlled, Cross-Over Study
Nutrients (2024) · Crossover · n=21
The results indicated no significant difference in the number of rounds completed between the CM and placebo conditions (13.5 ± 5.2 vs. 13.8 ± 6.7 rounds, respectively; p = 0.587).
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=1376204
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=4558
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).
At 6 g, a single dose before resistance exercise did not change soreness over 72 hours in a double-blind crossover of 9 untrained men (PMID 29057836). At 8 g the three trials disagree. In a crossover of 41 men, soreness was 40% lower at 24 and 48 hours, and 14.63% reported stomach discomfort (PMID 20386132). In 19 resistance-trained adults doing German Volume Training, total soreness was lower than on placebo (PMID 30458655). In recreationally active adults on an isokinetic version of the same protocol, soreness was higher with citrulline malate over 72 hours (PMID 30097067). The effect at 8 g is set low for that reason. No trial compared doses. A meta-analysis of 13 trials, where 8 g was the most frequent dose, found less soreness at 24 hours but not at 48 or 72 hours (PMID 33308806).
AI-estimated from published studies. Interpret as directional guidance.
Iron has a higher evidence score (9/10 vs 6/10) and wins in 2 of 3 categories.
For boost daily energy, Iron has a higher relevance score (90 vs 70).
No documented interaction was found in the data searched. This does not establish that this exact combination is safe.
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The right pick depends on your goals. Answer a few quick questions for a personalised recommendation — or dig into the full evidence on each.