Common Name(s): L-citrulline,2-amino-5-ureidopentanoic acid

CAS Number: 372-75-8

DESCRIPTION

What It Does: Provides arginine precursor activity for nitric oxide synthesis supporting skin microcirculation.

Why It's Used: Microcirculation-enhancing amino acid that provides arginine for no synthesis with potentially greater bioavailability than direct arginine supplementation.

How It Works: Citrulline is converted to arginine by argininosuccinate synthase, bypassing intestinal and hepatic arginine metabolism for more efficient systemic and local delivery to skin.

Typically Found In: Anti-fatigue formulations,microcirculation products

TECHNICAL DETAILS

Primary Category: Active ingredient – urea cycle amino acid

Secondary Functions: Microcirculation,arginine precursor

Application Areas:

Typical Concentration Range: 0.5%–3%

SOURCING & ETHICS

Vegan Status: Yes – plant-derived or synthetic

Halal Status: Yes

Source Notes: Fermentation-derived or synthetic. natural skin component.

SKIN COMPATIBILITY

Irritancy Rating: 1/5 – very low

Comedogenicity Rating: 0/5 – non-comedogenic

Sensitivity Concerns: Non-irritating; endogenous skin molecule.

Safe for Sensitive Skin: Yes

SAFETY & COMPATIBILITY

Safety Profile: Excellent safety profile. natural skin nmf component. ewg score: 1.

Works Well With: Hyaluronic acid,ceramides,peptides,other amino acids

Avoid Combining With: No significant incompatibilities

SCIENTIFIC NOTE

Citrulline bypasses the intestinal absorption limitations of arginine and the hepatic first-pass metabolism that degrades orally-consumed arginine before it reaches peripheral tissues. this makes citrulline a more efficient arginine precursor for peripheral no synthesis, including in skin.

Last Verified: 2026-03-12

Primary Sources: Cosing database,cir safety assessment