Ingredients / Amino acids & muscle

Citrulline

Also listed as: L-citrulline, citrulline malate

What it is

An amino acid that your body converts into arginine, which is used to make nitric oxide. Watermelon is a natural source.

Why it is in energy drinks

Marketed for blood flow ("pump") and endurance in pre-workouts.

Worth knowing

Studies that find a benefit generally use several grams, and the overall results are small and mixed, so the amount matters.

General information, not medical advice. We read what the label lists and don't test what an ingredient does.