The Claim

L-citrulline derived from watermelon is better tolerated than L-arginine supplements at doses up to 15 g/day, with no gastrointestinal side effects reported, due to its avoidance of hepatic metabolism and utilization of a distinct intestinal absorption pathway.

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

What the research says

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How it works
1 study reviewed
In plain English

L-citrulline from watermelon causes no gastrointestinal side effects at doses up to 15 grams per day, while L-arginine supplements do, because L-citrulline is absorbed differently in the intestines and does not pass through the liver first.

See the scientific wording

L-citrulline from watermelon is better tolerated than L-arginine supplements, with no gastrointestinal side effects reported at doses up to 15 g/day, due to its bypass of hepatic metabolism and distinct intestinal absorption pathway.

Why this might work

L-citrulline from watermelon is absorbed in the lower intestine without being broken down by the liver, travels directly to the kidneys, and gets turned into L-arginine there. This L-arginine then enters the bloodstream and is used by blood vessels to make nitric oxide, which relaxes them. Because L-citrulline avoids the liver and gut enzymes that break down L-arginine supplements, it does not trigger stomach upset even at high doses.

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

    Watermelon gives your body L-citrulline, which gets turned into a helpful molecule without passing through the liver like L-arginine supplements do — and because of that, it’s less likely to upset your stomach, even at higher amounts.

Score breakdown, mechanism chain, raw evidence, ideal studies needed & 1 supporting studies

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