What is L-Norvaline?

What is it?

L-Norvaline is an analog of the branched chain amino acid, valine. It can be found in foods such as dairy, meat, grains, soy and peanuts. Since valine is an essential amino acid, L-Norvaline has to be obtained through the diet, as the body cannot produce it.

What does it do?

L-Norvaline is involved in the indirect increase of nitric oxide levels in the blood. Nitric oxide has been shown to cause relaxation in the blood vessels. This vasodilatation may help to treat heart problems and lower blood pressure. When nitric oxide production is not properly produced, an individual may have health problems such as hypertension, obesity, diabetes, heart failure, and arteriosclerosis.

How does it work?

L-Norvaline is an inhibitor of the enzyme, arginase. Arginase is an enzyme that is used to break down and remove arginine into urea. Arginine has been shown to be a precursor to nitric oxide. Thus, the inhibiting of arginase will increase the concentration of arginine and more will be converted into nitric oxide. The nitric oxide has the effect on the body.


Very little research has been done specifically testing the effects of L-Norvaline due to its complex and indirect pathway to producing nitric oxide.

One study done at Texas A&M University by Chang Chiung, James Liao, and Lih Kuo tested the effects of L-Norvaline on nitric oxide in mouse macrophages. The study lasted 22 hours and used L-Norvaline and arginine to see if a threshold would occur when the two components were mixed. The macrophages were given varying doses arginine between 0.01mM and 0.8mM and 10 mM of L-Norvaline. The results showed that increasing arginine levels by .5 mM increased nitric oxide levels by 28% while adding 10 mM of L-Norvaline increased levels by 55%. The 10mM of L-Norvaline did increase urea production by 50% though. The final result showed that raising arginine levels by more than .5mM abolished all effects of L-Norvaline.

Dosage Recommendation:

There are no recommendations at this time for L-Norvaline. The toxicity at this time is also unknown.


It would be assumed that L-Norvaline consumption is adequate in a well balanced diet. Since it is an analog of valine, proper protein intake is necessary for correct L-Norvaline consumption.


More research needs to be done on the effects of L-Norvaline. The mechanism for the molecule seems to make sense, but it has not been identified to help athletic performance in any way.