The Claim

Consumption of watermelon pulp or rind increases plasma L-citrulline and L-arginine concentrations in humans, and the magnitude of this increase varies according to the form consumed and the individual's baseline vascular health.

Source: Watermelon Nutritional Composition with a Focus on L-Citrulline and Its Cardioprotective Health Effects—A Narrative Review

What the research says

Roughly balanced

Support and challenge are close. The picture may shift as more studies come in.

Supports
1score
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.

Cause and effect
1 study reviewed
In plain English

Eating watermelon pulp or rind raises levels of L-citrulline and L-arginine in the blood, and how much they rise depends on whether the pulp or rind is eaten and the person's vascular health before consumption.

See the scientific wording

Consumption of watermelon pulp or rind increases plasma L-citrulline and L-arginine concentrations in humans, but the magnitude of increase depends on the form consumed and the baseline vascular health of the individual.

Why this might work

When you eat watermelon, the L-citrulline in it gets absorbed directly into the blood without being broken down by the liver. It travels to the kidneys, where it is turned into L-arginine. This L-arginine then moves into blood vessel walls, where it is used to make nitric oxide, a molecule that relaxes blood vessels. In people with poor vascular health, an enzyme called arginase steals L-arginine and stops it from making nitric oxide; L-citrulline reduces this stealing, so more nitric oxide is made. Antioxidants in watermelon also protect nitric oxide from being destroyed by harmful molecules in the blood.

Verified mechanismbased on 1 study

What the research says

1 study
  1. Study: Watermelon Nutritional Composition with a Focus on L-Citrulline and Its Cardioprotective Health Effects—A Narrative Review

    Eating watermelon, especially the rind, boosts certain blood chemicals that help relax blood vessels, and this works better in people who already have high blood pressure or are overweight.

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.