The Claim

Citrulline metabolism increases nitric oxide production in vascular endothelium, resulting in vasodilation and enhanced oxygen delivery to skeletal muscle.

Source: Scientists Tested 13 Beverages - This Was the Best for Recovery, Hydration and Fat Loss

What the research says

Supports is higher

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

Supports
80score
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.

How it works
3 studies reviewed
In plain English

When citrulline is metabolized, it leads to increased nitric oxide production in blood vessel lining cells, which causes blood vessels to widen and improves oxygen delivery to skeletal muscle.

See the scientific wording

Citrulline metabolism increases nitric oxide production in vascular endothelium, resulting in vasodilation and enhanced oxygen delivery to skeletal muscle.

Why this might work

Citrulline is absorbed from the gut and turned into arginine in the kidneys. Arginine enters the bloodstream and is used by blood vessel lining cells to make nitric oxide. Nitric oxide spreads to nearby muscle cells in the vessel wall, causing them to relax and widen the blood vessels. This allows more blood and oxygen to flow into skeletal muscle, improving how well the muscle works during activity.

Verified mechanismbased on 5 studies

What the research says

3 studies

  1. Study: Citrulline Supplementation Improves Microvascular Function and Muscle Strength in Middle-Aged and Older Adults with Type 2 Diabetes

    Taking citrulline supplements helped widen small blood vessels in the legs of older adults with diabetes, which let more oxygen reach their muscles and made their leg strength slightly better.

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

    Taking citrulline helped people walk farther in 6 minutes and reduced a marker of blood vessel inflammation, which suggests their blood vessels worked better — likely because more nitric oxide was made to help them widen.

  3. Study: Biochemical, physiological, and performance response of a functional watermelon juice enriched in L-citrulline during a half-marathon race

    Drinking watermelon juice with citrulline raised arginine levels in the blood, which helps blood vessels relax and deliver more oxygen to muscles, reducing soreness and waste buildup after exercise.

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Read analysis

Score breakdown, mechanism chain, raw evidence, ideal studies needed & 3 supporting studies

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