The Claim

Supplementation with 300 mL/day of watermelon juice concentrate for 16 days increases resting systolic blood pressure by approximately 6 mmHg in healthy recreationally-active adult males compared to a control condition, despite increasing nitric oxide biomarkers.

Source: Two weeks of watermelon juice supplementation improves nitric oxide bioavailability but not endurance exercise performance in humans.

What the research says

Supports is higher

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

Supports
46score
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

Drinking 300 mL of watermelon juice concentrate daily for 16 days raises resting systolic blood pressure by about 6 mmHg in healthy, active adult men, even though it also raises markers of nitric oxide in the blood.

See the scientific wording

Supplementation with 300 mL/day of watermelon juice concentrate for 16 days increases resting systolic blood pressure by approximately 6 mmHg in healthy recreationally-active adult males compared to a control condition, despite increasing nitric oxide biomarkers.

Why this might work

The body absorbs L-citrulline from watermelon juice, converts it to arginine, and uses it to make large amounts of nitric oxide. This excess nitric oxide overactivates blood vessel relaxation, causing the body to respond by tightening blood vessels elsewhere to maintain pressure, which raises resting systolic blood pressure.

Verified mechanismbased on 1 study

What the research says

1 study
  1. Study: Two weeks of watermelon juice supplementation improves nitric oxide bioavailability but not endurance exercise performance in humans.

    Drinking this special watermelon juice for two weeks made healthy men’s blood pressure go up by about 6 points, even though their bodies made more of a chemical that usually lowers blood pressure. So yes, it happened — just like the claim said.

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.