Benefits of L-Arginine

Evidence-Based Benefits

• Blood pressure reduction — a 2011 meta-analysis of 11 RCTs found L-arginine lowered systolic BP by 5.39 mmHg and diastolic by 2.66 mmHg (Dong et al., American Heart Journal)
• Endothelial function — arginine improves flow-mediated dilation (FMD) in patients with cardiovascular risk factors (Bai et al., 2009)
• Erectile dysfunction — a 2019 meta-analysis of 10 RCTs found L-arginine significantly improved erectile function scores vs placebo (Rhim et al., Journal of Sexual Medicine)
• Exercise performance — L-arginine may increase exercise tolerance by improving blood flow to working muscles, though results are mixed (Bailey et al., 2010)
• Wound healing — arginine supports collagen synthesis and immune cell function at wound sites (Stechmiller et al., 2005)

What the Research Says

L-Arginine has solid evidence for blood pressure reduction (meta-analysis: -5.4 mmHg systolic) and emerging evidence for erectile dysfunction. However, its bioavailability is limited by extensive first-pass metabolism via arginase in the gut and liver. L-Citrulline bypasses this metabolism and may be more effective at sustaining elevated arginine and NO levels. Arginine remains useful for wound healing and as part of cardiovascular support protocols.

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