Evidence Level
L-Arginine is a semi-essential amino acid with established benefits for cardiovascular health and emerging evidence for other applications. A meta-analysis of randomized controlled trials by Dong et al. (2011) demonstrated that oral L-arginine supplementation significantly reduces systolic blood pressure, with an average reduction of -5.4 mmHg. This effect is supported by additional studies, including a dose-response meta-analysis by Shiraseb et al. (2022), which further validates its role in blood pressure management.
L-Arginine also shows promise for erectile dysfunction, as evidenced by a systematic review and meta-analysis by Rhim et al. (2019). The study highlights the potential of L-arginine to improve sexual function, particularly when combined with other therapies such as Pycnogenol® (Tian et al., 2023). However, its bioavailability is limited due to extensive first-pass metabolism via arginase in the gut and liver. This limitation has led to interest in L-Citrulline as an alternative, which bypasses this metabolic pathway and may sustain elevated levels of arginine and nitric oxide more effectively (Schwedhelm et al., 2008).
Beyond cardiovascular and sexual health, L-arginine has been studied for its potential in other areas. For instance, a systematic review by Makama et al. (2025) suggests that it may reduce the risk of pre-eclampsia in pregnancy, though evidence remains limited. Additionally, research by Mohammadi et al. (2024) indicates that L-arginine supplementation can improve biomarkers of cardiac function and inflammation in patients undergoing coronary artery bypass graft surgery.
Despite these benefits, some studies have shown mixed results. For example, a systematic review by Karimi et al. (2023) found no significant effect of L-arginine on glycemic control markers, while Porto et al. (2023) reported no impact on inflammation or oxidative stress after exercise.
Overall, L-arginine remains a valuable supplement for specific applications, particularly in cardiovascular support and wound healing, though its limitations in bioavailability should be considered when evaluating its use.