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Head-to-head evidence comparison — which supplement is right for you?
Arginine vs L-Citrulline: Arginine has the stronger overall evidence (7.5 vs 6/10); they're alternatives for improve endurance — the best pick depends on your goals. Take the 60-second quiz for a pick tailored to your goals.
Arginine wins 2 of 3 categories. Both are solid choices — the best pick depends on your specific goals.
Verdict
Likely helps
8 of 11 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 Arginine and L-Citrulline have evidence — compare verdict strength side-by-side.
3-6g daily
30-60 minutes before exercise, Divided doses throughout the day for cardiovascular benefits
L-Arginine powder or capsules
3-6g (or 6-8g citrulline malate)
30-60 minutes before exercise, Or split doses throughout day
L-Citrulline powder (pure form)
30-60 minutes
During exercise
2-4 weeks
Immediate
1-2 weeks
24-48 hours post-exercise
30-60 minutes
With doses >10g
Nutritional interventions for preventing and treating pressure ulcers
The Cochrane database of systematic reviews (2024) · Meta analysis · n=7920
Compared to standard diet, protein supplements may result in little to no difference in pressure ulcer incidence (protein 21 per 1000, standard diet 28 per 1000; RR 0.75, 95% CI 0.49 to 1.14; 4 studies, 4264 participants; low-certainty evidence).
Comparative Effects of Different Nutritional Supplements on Inflammation, Nutritional Status, and Clinical Outcomes in Colorectal Cancer Patients: A Systematic Review and Network Meta-Analysis
Nutrients (2023) · Meta analysis · n=2841
Glutamine was superior in decreasing tumor necrosis factor-α (MD -25.2; 95% CrI [-32.62, -17.95]), whereas combined omega-3 and arginine supplementation was more effective in decreasing interleukin-6 (MD -61.41; 95% CrI [-97.85, -24.85]).
Nutritional interventions for treating foot ulcers in people with diabetes
The Cochrane database of systematic reviews (2020) · Meta analysis · n=629
It is also uncertain whether arginine, glutamine and β-hydroxy-β-methylbutyrate supplement increases the proportion of ulcers healed at 16 weeks compared with placebo (RR 1.09, 95% CI 0.85 to 1.40).
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).
From a dose-response meta-analysis of twenty-two randomised placebo-controlled trials (PMID 34967840): oral L-arginine lowered systolic blood pressure by 6.40 mmHg and diastolic by 2.64 mmHg overall, the effective dose for systolic pressure was 4 g a day or more, and trials using more than 9 g a day showed no significant change. That subgroup result is why the curve falls back at 9 g. It is a subgroup of pooled trials, not a trial that compared doses, so no optimal dose is given. An earlier meta-analysis of 11 trials at 4 to 24 g a day (PMID 22137067) found similar reductions (5.39 and 2.66 mmHg) without separating doses. Neither abstract reports side effects by dose.
AI-estimated from published studies. Interpret as directional guidance.
Arginine has a higher evidence score (7.5/10 vs 6/10) and wins in 2 of 3 categories.
For improve endurance, L-Citrulline has a higher relevance score (85 vs 65).
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.