I'm using it daily. Orally supplemented arginine has a very low bioavailability, and may even harm the liver, depending on the amount of intake. But you can circumvent this issue by supplementing with citrulline. The reason is the arginine-citrulline-NO cycle. Nitric oxide synthase is the enzyme that produces NO from arginine precursor. One fallout product of this reaction is citrulline. Then there are two more enzymes that convert citrulline back to arginine. You can imagine that adding citrulline to this cycle will indirectly increase arginine. The beauty of this is that citrulline supplementation has no side effects, and orally taken citrulline has a high bioavailability. That’s the major reason why I take citrulline daily as a supplement.