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Head-to-head evidence comparison — which supplement is right for you?
L-Citrulline wins 2 of 3 categories. Both are solid choices — the best pick depends on your specific goals.
Verdict
Likely helps
5 of 5 studies with measurable effects showed benefit.
Top outcomes
Verdict
Likely helps
8 of 10 studies with measurable effects showed benefit.
Top outcomes
Shared outcomes (1)
Outcomes where both Alpha-GPC and L-Citrulline have evidence — compare verdict strength side-by-side.
300-600mg daily
Morning for cognitive enhancement, 30-60 min before workout for performance
Alpha-GPC 50% 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)
1-2 hours
2-4 weeks
Acute
Same day
1-2 weeks
24-48 hours post-exercise
30-60 minutes
With doses >10g
L-Alpha-Glycerylphosphorylcholine (L-α-GPC): A Comprehensive Review of Its Preparation Techniques and Versatile Biological Effects
Journal of food science (2025) · Systematic review
Due to its high choline content (41% by weight) and ability to cross the blood-brain barrier, GPC is considered one of the most utilized sources of choline.
Activity of Choline Alphoscerate on Adult-Onset Cognitive Dysfunctions: A Systematic Review and Meta-Analysis
Journal of Alzheimer's disease : JAD (2023) · Meta analysis · n=1326
We found significant effects of α-GPC in combination with donepezil on cognition [4 RCTs, mean difference (MD):1.72, 95% confidence interval (CI): 0.20 to 3.25], functional outcomes [3 RCTs, MD:0.79, 95% CI: 0.34 to 1.23], and behavioral outcomes [4 RCTs; MD: -7.61, 95% CI: -10.31 to -4.91].
Revisiting choline alphoscerate profile: a new, perspective, role in dementia?
The International journal of neuroscience (2013) · Systematic review
Choline alphoscerate (alpha-glyceryl-phosphorylcholine, alpha-GPC) is a semisynthetic derivative of phosphatidylcholine with central parasympathomimetic action.
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 · n=1080
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).
Based on RCTs showing cognitive improvements in healthy adults and dementia patients. Effect sizes were modest and some studies used combination therapy. Higher doses associated with increased headache risk.
Meta-analysis showed significant reduction in muscle soreness 24h post-exercise but effect size was modest. Studies primarily used citrulline malate form.
AI-estimated from published studies. Interpret as directional guidance.
L-Citrulline has a higher evidence score (9/10 vs 8.5/10) and wins in 2 of 3 categories.
For athletic performance, L-Citrulline has a higher relevance score (80 vs 60).
No known interactions between Alpha-GPC and L-Citrulline have been documented in our database. However, always consult a healthcare provider before combining supplements.