L-Arginine, ranked by real cost

L-Arginine is an amino acid your body uses to make nitric oxide, the compound that helps blood vessels relax and dilate. That's why it's sold as a "pump" or circulation supplement. The evidence picture is mixed. Oral L-Arginine consistently produces small reductions in blood pressure (roughly 5 points systolic) at doses of 4-24g/day in clinical trials. For exercise performance, the "pump" most users are chasing, direct evidence is weaker — most studies show limited benefit over placebo. Here's something worth knowing: L-Citrulline (also on TrueServing) actually outperforms L-Arginine for nitric oxide production in most direct comparisons. L-Arginine gets broken down heavily on first pass through the liver before it can raise blood arginine levels; L-Citrulline doesn't, and converts to arginine once it reaches the bloodstream. If you're buying for circulation or pump, L-Citrulline is often the better choice at a comparable or lower cost. Research doses are higher than most commercial products. Many capsules contain 500mg-1g, meaning hitting a research dose requires taking many capsules per day. Products below are ranked by cost at your chosen daily dose.