The Claim

In adults with short bowel syndrome and baseline plasma citrulline below 20 μmol/L, oral citrulline supplementation increases non-oxidative leucine disposal.

Source: Effect of oral citrulline supplementation on whole body protein metabolism in adult patients with short bowel syndrome: A pilot, randomized, double-blind, cross-over study.

What the research says

Supports is higher

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

Supports
58score
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
1 study reviewed
In plain English

In adults with short bowel syndrome and low blood citrulline levels, taking citrulline by mouth increases the rate at which leucine is used for building proteins rather than being burned for energy.

See the scientific wording

In adults with short bowel syndrome and baseline plasma citrulline below 20 μmol/L, oral citrulline supplementation increases non-oxidative leucine disposal, suggesting a potential anabolic effect specifically in those with severe citrulline deficiency.

Why this might work

When citrulline levels are very low, the body cannot make enough arginine, which stops the process that directs leucine into building new proteins. Giving citrulline back lets the body make arginine again, which then turns on the machinery that uses leucine to build muscle and other proteins instead of burning it for energy.

Supported mechanismbased on 1 study

What the research says

1 study
  1. Study: Effect of oral citrulline supplementation on whole body protein metabolism in adult patients with short bowel syndrome: A pilot, randomized, double-blind, cross-over study.

    In people with a very short intestine and extremely low citrulline levels, taking citrulline pills helped their bodies use protein better — but only in those with the lowest levels. Others didn’t see the same benefit.

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

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