L-arginine
Meaning of L-arginine: L-arginine is an amino acid the body uses to build protein and to produce nitric oxide, a molecule that widens blood vessels.
Definition of L-arginine
L-arginine, commonly called arginine, is one of the amino acids the body uses as a building block for protein. It is considered conditionally essential, meaning the body can normally produce enough on its own but may need additional dietary intake during illness, injury, or periods of rapid growth.
Beyond its role in protein synthesis, arginine serves as the raw material the body converts into nitric oxide, a signaling molecule that relaxes and widens blood vessels, and it also contributes to wound healing and immune function. Arginine is found naturally in protein rich foods such as meat, dairy, nuts, and seeds.
Arginine is also sold as a dietary supplement, marketed for purposes including exercise performance and circulatory support, though evidence for many specific claimed benefits of supplementation is limited, and supplement doses considerably exceed the amounts typically obtained through diet alone.
Also known as
Used in a sentence
The patient reported taking an L-arginine supplement in addition to a regular diet.
Good to know
Arginine obtained through ordinary diet differs considerably in amount from concentrated supplement doses, a distinction relevant when evaluating claims made about supplemental arginine use.
Word origin
Where “L-arginine” comes from
Formed from Greek argos, meaning bright or silver, reflecting the silver salt form in which the amino acid was first isolated.