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Head-to-head evidence comparison — which supplement is right for you?
Caffeine wins 2 of 3 categories. Both are solid choices — the best pick depends on your specific goals.
Verdict
Likely helps
22 of 25 studies with measurable effects showed benefit.
Top outcomes
Verdict
Likely helps
3 of 4 studies with measurable effects showed benefit.
Top outcomes
Shared outcomes (2)
Outcomes where both Caffeine and Citrulline Malate have evidence — compare verdict strength side-by-side.
100-200mg
Morning, 30-60 minutes before exercise
Pill/capsule for precise dosing
6-8g citrulline malate pre-workout
30-60 minutes before exercise, Empty stomach or with light carbs
Citrulline Malate 2:1 powder
15-45 minutes
30-60 minutes
30-60 minutes
30-60 minutes
Acute (within session)
Acute
24-48 hours
Acute
Effect of Acute Caffeine Intake on the Fat Oxidation Rate during Exercise: A Systematic Review and Meta-Analysis
Nutrients (2020) · Meta analysis · n=2020
A subsequent meta-analysis was performed using the random effects model to calculate the standardized mean difference (SMD).
The effects of caffeine intake on weight loss: a systematic review and dos-response meta-analysis of randomized controlled trials
Critical reviews in food science and nutrition (2019) · Meta analysis · n=606
Thirteen RCTs with 606 participants were included in the meta-analyses.
Effect of Caffeine and Nitrates Combination on Exercise Performance, Heart Rate and Oxygen Uptake: A Systematic Review and Meta-Analysis
Nutrients (2024) · Meta analysis · n=95
The meta-analysis revealed that caffeine and nitrates supplementation (CAF+nitrates) did not enhance performance in time trials (TTs) over the CAF alone (g = -0.06; 95% CI = -0.46 to 0.35; p = 0.78) or nitrates alone (g = 0.29; 95% CI = -0.12 to 0.70; p = 0.17).
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=198
Small ergogenic effect (SMD=0.196)
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=60
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).
Based on multiple meta-analyses showing 3-6mg/kg optimal dosing. Performance benefits plateau around 200-300mg with increased jitteriness at higher doses.
Meta-analysis showed small effect (SMD=0.196) with ~3 additional reps. Several individual studies showed mixed results including null findings. Effect appears inconsistent across different exercise modalities.
AI-estimated from published studies. Interpret as directional guidance.
Caffeine has a higher evidence score (9.5/10 vs 7.5/10) and wins in 2 of 3 categories.
For boost daily energy, Caffeine has a higher relevance score (98 vs 70).
No known interactions between Caffeine and Citrulline Malate have been documented in our database. However, always consult a healthcare provider before combining supplements.