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Head-to-head evidence comparison — which supplement is right for you?
Beta-Alanine vs L-Citrulline: Beta-Alanine has the stronger overall evidence (7.5 vs 6/10); they're alternatives for athletic performance — the best pick depends on your goals. Take the 60-second quiz for a pick tailored to your goals.
Beta-Alanine wins 2 of 3 categories. Both are solid choices — the best pick depends on your specific goals.
Verdict
Likely helps
5 of 7 studies with measurable effects showed benefit.
Top outcomes
Verdict
Likely helps
3 of 4 studies with measurable effects showed benefit.
Top outcomes
Shared outcomes (1)
Outcomes where both Beta-Alanine and L-Citrulline have evidence — compare verdict strength side-by-side.
3.2-6.4g daily
Anytime - timing doesn't affect carnosine buildup
CarnoSyn® sustained-release tablets
3-6g (or 6-8g citrulline malate)
30-60 minutes before exercise, Or split doses throughout day
L-Citrulline powder (pure form)
2-4 weeks
2-4 weeks
15-30 minutes post-dose
1-2 weeks
24-48 hours post-exercise
30-60 minutes
With doses >10g
Beta-alanine supplementation and exercise performance: A meta-analysis
British Journal of Sports Medicine (2017) · Meta analysis · n=1461
Significant improvement in exercise capacity
ISSN position stand: Beta-alanine
Journal of the International Society of Sports Nutrition (2015) · Review
Increases muscle carnosine by 40-80%
Effects of different dietary supplements on athletic performance in soccer players: a systematic review and network meta-analysis
Journal of the International Society of Sports Nutrition (2025) · Meta analysis · n=1425
Kaempferia parviflora (SMD: 0.46, small) was associated with a significant effect on enhancing muscular strength.
Absence of Effects of L-Arginine and L-Citrulline on Inflammatory Biomarkers and Oxidative Stress in Response to Physical Exercise: A Systematic Review with Meta-Analysis
Nutrients (2023) · Meta analysis
We observed no difference between pre- vs. post-exercise for oxidative stress (subtotal = -0.21 [CI: -0.56, 0.14], p = 0.24, and heterogeneity = 0%.
Effects of Citrulline or Watermelon Supplementation on Body Composition: A Systematic Review and Dose-Response Meta-Analysis
Nutrients (2025) · Meta analysis
Overall, CIT supplementation had no substantial effects on body mass index (BMI), body weight, fat mass (FM), waist circumference (WC), body fat percentage (BFP), and fat-free mass (FFM).
Effect of food sources of nitrate, polyphenols, L-arginine and L-citrulline on endurance exercise performance: a systematic review and meta-analysis of randomised controlled trials
Journal of the International Society of Sports Nutrition (2021) · Meta analysis
No effect on exercise performance following consumption of foods rich in L-citrulline was identified (SMD=-0.03, p=0.24).
The two points come from two separate small placebo-controlled trials, and neither compared doses. At 4.8 g a day for 30 days, 8 resistance-trained men completed 22% more squat repetitions than with placebo (PMID 18548362). At 6.4 g a day for 4 weeks, 23 highly-trained judo athletes made more throws in a judo fitness test, with no change with placebo (PMID 27601217). The outcomes differ, so the equal heights mean only that both doses helped, not that 6.4 g adds nothing over 4.8 g. A 7-day trial in 11 World Tour cyclists at 20 g a day (four 5 g servings) improved uphill time-trial power (PMID 39226288), but that short loading protocol is not comparable with weeks of daily dosing and is not plotted. Neither plotted trial reports side effects in its abstract, so no ceiling is given. Reviews put the effective range at 4 to 6.4 g a day (PMID 26175657, PMID 40995761) without comparing doses within a trial.
AI-estimated from published studies. Interpret as directional guidance.
Beta-Alanine has a higher evidence score (7.5/10 vs 6/10) and wins in 2 of 3 categories.
For athletic performance, Beta-Alanine has a higher relevance score (95 vs 80).
No documented interaction was found in the data searched. This does not establish that this exact combination is safe.
The right pick depends on your goals. Answer a few quick questions for a personalised recommendation — or dig into the full evidence on each.