Optimum Nutrition
THE BIOHACKING STANDARD
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L-arginine is a conditionally-essential amino acid and the substrate for endothelial nitric oxide synthase (eNOS). Evidence is mixed and dose-sensitive: at 3-6 g doses acutely it can transiently raise plasma arginine and produce mild vasodilation, but oral bioavailability is limited by first-pass metabolism and the acute NO effect is often modest compared to L-citrulline, which bypasses hepatic arginase and raises plasma arginine more effectively. Chronic L-arginine (5-9 g/day) has some evidence for erectile function in mild ED, blood pressure in specific populations, and post-surgical wound healing. It notably failed the VINTAGE-MI trial after myocardial infarction (increased mortality signal), which is why post-MI patients specifically should avoid it. Bulkessentials sells L-arginine as a single-ingredient powder — good for transparency and dose flexibility. Scored Standard: a real, well-characterized amino acid with legitimate use cases but a modest evidence base compared to L-citrulline for the same endpoints.
The Vyvata score's Evidence dimension measures the quality of published RCT support for a product's active ingredients at the label dose. Our source hierarchy: double-blind RCTs in MEDLINE-indexed journals > single-blind RCTs > open-label trials > observational studies > mechanism papers > N=1 case studies (anecdotes). Predatory journals and manufacturer-authored studies without independent replication are weighted down.
Product-specific evidence citations for this item are embedded in the analysis text on the "Analysis" tab. For the full framework and evidence hierarchy, see the methodology page.
FAQ data has not been generated for this product yet. See the site FAQ for general questions.
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