L-Citrulline
The store positions it as supporting healthy nitric-oxide production and blood flow already within a normal range.
Our read: The best-understood mechanism in the bottle. Citrulline is converted to arginine in the kidneys, which raises nitric oxide more reliably than swallowing arginine itself does. The honest caveat: the exercise studies people quote use gram-scale doses, and no milligram amount is published for this product — so read the panel on the bottle.


