The Claim

L-citrulline supplementation at 4 g/day for three months does not significantly reduce endothelin-1, sE-selectin, or VCAM-1 levels in adults recovering from severe COVID-19, despite reducing ICAM-1 levels.

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.

Description
1 study reviewed
In plain English

In adults recovering from severe COVID-19, taking 4 grams of L-citrulline daily for three months lowers ICAM-1 but does not lower endothelin-1, sE-selectin, or VCAM-1.

See the scientific wording

L-citrulline supplementation at 4 g/day for three months does not significantly reduce endothelin-1, sE-selectin, or VCAM-1 levels in adults recovering from severe COVID-19, despite reducing ICAM-1, suggesting selective effects on specific endothelial activation markers.

Why this might work

L-citrulline is turned into arginine in the kidneys, which the blood vessel lining uses to make more nitric oxide. This nitric oxide reduces one specific protein called ICAM-1 that sticks white blood cells to blood vessels, but it does not change other proteins like endothelin-1, sE-selectin, or VCAM-1 that control different aspects of blood vessel inflammation.

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

    L-citrulline pills helped reduce one sign of blood vessel inflammation (ICAM-1) in people recovering from severe COVID-19, but didn’t change other similar signs. So it works on some markers but not others.

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.