Citrulline and arginine
L-citrulline, citrulline malate 2:1, L-arginine and AAKG: what these amino acids are, how the forms differ and how much pre-workouts contain.
This substance has no health claim authorised in the European Union. So we describe what it is and how it is taken, but do not say what it does in the body.
What they are
Citrulline and arginine are amino acids the body makes itself. Citrulline is named after the watermelon (Citrullus lanatus), which is rich in it; arginine is in meat, fish, nuts and seeds. Both are in many pre-workouts.
No claims about what citrulline or arginine do are authorised in the European Union. So we do not write about "pump", blood flow or endurance; we explain how to compare products.
Forms
L-citrulline is the pure amino acid. Citrulline malate 2:1 is citrulline bound to malic acid, about two-thirds citrulline. So 6 g of citrulline malate is roughly 4 g of citrulline.
L-arginine is sold pure and as AAKG (arginine alpha-ketoglutarate). In pre-workouts citrulline is now more common than arginine.
How they are taken
Makers of stand-alone citrulline malate usually state 6–8 g, of L-citrulline 3–6 g, 30–60 minutes before training. Pre-workouts vary widely — 1 to 8 g — so check the composition table. People on blood-pressure medicines or nitrates should ask a doctor first.
Frequently asked questions
How is citrulline different from citrulline malate?
Citrulline malate 2:1 is bound to malic acid and is about two-thirds citrulline. Compare the citrulline itself.
Which is better, citrulline or arginine?
They are different amino acids. Modern pre-workouts more often use citrulline; it depends on the product's recipe.
Can it be combined with caffeine?
Many pre-workouts contain both. Count the day's total caffeine.
Citrulline & arginine in the shop
