Benefits of L-Citrulline

Evidence-Based Benefits

• Exercise performance — Trexler et al. (2019, meta-analysis, 12 RCTs) found citrulline significantly improved high-intensity exercise performance (cycling and resistance exercise)
• Arginine elevation — Schwedhelm et al. (2008, n=20) showed citrulline raises plasma arginine levels more effectively than equimolar arginine supplementation
• Fatigue reduction — Pérez-Guisado & Jakeman (2010, n=41) found citrulline malate 8 g reduced bench press fatigue and post-exercise muscle soreness by 40%
• Blood flow — citrulline-derived arginine is converted to nitric oxide by endothelial NOS, promoting vasodilation and improved exercise blood flow

What the Research Says

L-Citrulline is an amino acid that enhances nitric oxide production and improves exercise performance. Unlike arginine, which undergoes significant first-pass liver metabolism, L-citrulline bypasses this process, leading to higher plasma arginine levels per gram consumed (Schwedhelm et al., 2008). This characteristic makes it a more efficient precursor for arginine, particularly in contexts where rapid nitric oxide production is desired.

Several studies have demonstrated the benefits of L-Citrulline supplementation. A systematic review and meta-analysis by Trexler et al. (2019) found that acute citrulline supplementation significantly enhances high-intensity strength and power performance. Additionally, Luo et al. (2025) reported that L-citrulline supplementation reduces systolic (-4.02 mmHg, P=0.002) and diastolic (-2.54 mmHg, P=0.004) blood pressure in middle-aged and older adults, highlighting its potential cardiovascular benefits.

Citrulline malate (2:1) is a popular form used in pre-workout supplements due to its enhanced bioavailability and effectiveness. However, pure L-citrulline at lower doses has also been shown to be equally effective in improving exercise performance (Trexler et al., 2019). While some studies suggest that L-Citrulline may not significantly impact inflammatory biomarkers or oxidative stress responses to exercise (Porto et al., 2023), its role as a nitric oxide booster and performance enhancer remains well-supported by evidence.

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