Ingredients / Amino acids & muscle

L-arginine

What it is

An amino acid from protein foods that the body uses to make nitric oxide, a molecule that relaxes blood vessels.

Why it is in energy drinks

Marketed for blood flow and exercise performance.

Worth knowing

Taken by mouth it is broken down a lot before reaching the blood, which is why citrulline is often used instead.

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