The Claim

L-citrulline supplementation at 4 g/day for three months has no significant effect on plasma nitrite levels in adults recovering from severe COVID-19.

Source: Effect of L-Citrulline Supplementation on Endothelial Function and Body Composition in Post-COVID-19 Syndrome: A Randomized Clinical Trial

What the research says

Supports is higher

Support is ahead, but a single strong opposing study can change this.

Supports
74score
Challenges
0score

These are independent scores, not a percentage. Higher-grade studies count more, so a single strong opposing study can outweigh several weaker ones.

Quantitative
1 study reviewed
In plain English

Taking 4 grams of L-citrulline daily for three months does not change plasma nitrite levels in adults who have recovered from severe COVID-19.

See the scientific wording

L-citrulline supplementation at 4 g/day for three months does not significantly alter plasma nitrite levels in adults recovering from severe COVID-19, despite its proposed mechanism of enhancing nitric oxide bioavailability.

Why this might work

L-citrulline turns into L-arginine in the kidneys, which the blood vessels use to make nitric oxide. This nitric oxide opens up small blood vessels to improve blood flow and oxygen delivery to muscles. Even though more nitric oxide is made, it gets used up quickly by inflammation and broken down fast in the blood, so the amount of nitrite measured in the plasma does not go up.

Supported mechanismbased on 1 study

What the research says

1 study
  1. Study: Effect of L-Citrulline Supplementation on Endothelial Function and Body Composition in Post-COVID-19 Syndrome: A Randomized Clinical Trial

    The study gave people L-citrulline for three months and checked if their nitrite levels went up — they didn’t. So even though L-citrulline might help other things like walking farther, it didn’t raise the nitrite levels scientists use to measure nitric oxide.

Score breakdown, mechanism chain, raw evidence, ideal studies needed & 1 supporting studies

Fit Body Science verdict — we translate health claims into clear verdicts backed by peer-reviewed research.

Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.