Reassessment of the effect of oral L-arginine on blood pressure: A systematic review and meta-analysis based on ambulatory blood pressure monitoring

madman · 2026-09-07T18:28:16-0500

This study conducted a systematic review and meta-analysis to synthesize existing evidence from randomized controlled trials (RCTs) and evaluate the effect of oral L-arginine on ABP, aiming to provide a more robust evidence-based foundation for non-pharmacological adjunctive BP-lowering strategies.

6. Conclusions

Current evidence indicates that oral L-arginine supplementation significantly reduces 24-h, daytime, and nighttime BP. Given the limited number of included studies, further validation through rigorously designed RCTs with adequate sample sizes and longer intervention periods is warranted to confirm its long-term efficacy.

madman · 2026-09-07T18:30:38-0500

Fig. 2. Forest plot of the effect of oral L-Arginine on 24-hour blood pressure.

madman · 2026-09-07T18:31:11-0500

Fig. 3. Forest plot of the effect of oral L-Arginine on daytime blood pressure.

madman · 2026-09-07T18:31:44-0500

Fig. 4. Forest plot of the effect of oral L-Arginine on nighttime blood pressure.

madman · 2026-09-07T18:34:24-0500

Conclusion

As summarized in Table 2, current evidence indicates the preference for Cit over Arg administration for NO production. Because of more efficient intestinal absorption, low FPM, and high renal reabsorption, oral Cit compared with the same dose of Arg provides more systemic available Arg in a sustainable manner. Cit is a more powerful NO precursor than Arg because: (1) exogenous Cit increases intracellular Arg pools, (2) Cit transporters and ASS-ASL enzymes are co-localized and coinduced with NOS enzymes, and (3) Cit recycling pathway is found in NO-producing cells. In contrast, imported Arg seems to be more available for arginase rather than the NOSs, which effectively limits its accessibility for NO synthesis and shuttles Arg into other cellular pathways (e.g., production of ornithine and polyamines). The evidence strongly supports the hypothesis that extracellular sources of Arg can be utilized for other cellular requirements than NO production. On the other hand, side-effects (e.g., induction of arginase, disruption of ADMA metabolism, and inhibition of Cit recycling pathway), inhibit the usefulness of Arg supplementation for NO production. Since Cit is superior over Arg as a safe and effective precursor of NO production, its supplementation has further justification in medical practice.

Thread 'Citrulline the new star for increasing nitric oxide'

Oct 25, 2020

Endogenous flux of nitric oxide: Citrulline is preferred to Arginine

Abstract

Both arginine (Arg) and its precursor citrulline (Cit) have received much interest during the past two decades because of their potential effects on whole-body nitric oxide (NO) production and augmentation of NO-dependent signaling pathways. However, the usefulness of Arg supplementation for NO production is questionable due to its high splanchnic first-pass metabolism (FPM), which limits its systemic availability. Both hepatic- and extra-hepatic arginases critically...