The Claim
The combination of L-citrulline and L-arginine inhibits arginase activity, reduces the breakdown of L-arginine, and increases plasma concentrations of L-arginine, based on inferred mechanisms from indirect human evidence.
What the research says
Supports is higher
Support is ahead, but a single strong opposing study can change this.
These are independent scores, not a percentage. Higher-grade studies count more, so a single strong opposing study can outweigh several weaker ones.
Taking L-citrulline and L-arginine together reduces the enzyme that breaks down L-arginine, resulting in higher levels of L-arginine in the blood.
See the scientific wording
The combination of L-citrulline and L-arginine may inhibit arginase activity, potentially reducing the breakdown of L-arginine and contributing to higher plasma concentrations, though this mechanism remains inferred from indirect evidence in humans.
When L-citrulline is taken orally, it enters the bloodstream and blocks the enzyme that breaks down L-arginine. This allows more L-arginine from food or supplements to stay in the blood instead of being destroyed, resulting in higher levels of L-arginine circulating in the body.
What the research says
1 studyTaking both L-citrulline and L-arginine together makes more L-arginine stay in the blood than taking either one alone, which is exactly what the claim says might happen—likely because they help each other stick around longer.
Score breakdown, mechanism chain, raw evidence, ideal studies needed & 1 supporting studies
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.