Common Name(s): Arginine pca,arginine pca,arginine salt of nmf pca,natural moisturising factor humectant
CAS Number: N/a
DESCRIPTION
What It Does: Replenishes pca as an nmf component for hygroscopic moisture retention โ the 12% nmf contribution of pca directly maintaining sc softness and flexibility.
Why It's Used: Pca is the most physiologically compatible cosmetic humectant because it is native to healthy sc โ restoring nmf pca content addresses the specific deficiency in dry and ageing skin rather than adding foreign humectants.
How It Works: Pca (pyrrolidone carboxylic acid, 5-membered cyclic amide of glutamate) at skin ph 5.5 carries a single negative charge (pka 3.6) providing h-bonding water retention from the carboxylate and the ring carbonyl. in healthy skin, pca is produced by filaggrin hydrolysis โ urocanic acid โ pca, maintaining the 10-12% nmf free amino acid/pca fraction.
Typically Found In: Natural moisturisers,nmf-focused care,sensitive skin
TECHNICAL DETAILS
Primary Category: Active ingredient โ humectant
Secondary Functions: Moisture retention,hydration
Application Areas:
Facial Skincare
Body Care
Hair Care
Beard Care
Color Cosmetics (Makeup)
Dietary/Oral Supplements
Typical Concentration Range: 0.5%โ5%
SOURCING & ETHICS
Vegan Status: Conditional - feedstock declaration required
Halal Status: Unverified - feedstock declaration required (plant, animal and petrochemical routes all exist)
Source Notes: Plant-derived or fermentation-produced. [audit 2026-07-29 rev2: origin-dependent: the same inci exists in plant, animal and petrochemical versions and the name does not discriminate. determination requires shariah-panel sign-off.]
SKIN COMPATIBILITY
Irritancy Rating: 1/5 โ very low
Comedogenicity Rating: 0/5 โ non-comedogenic
Sensitivity Concerns: Non-irritating; suitable for sensitive skin.
Safe for Sensitive Skin: Yes
SAFETY & COMPATIBILITY
Safety Profile: Excellent safety profile. ewg score: 1.
Works Well With: Ceramides,emollients,occlusives,barrier actives
Avoid Combining With: No significant incompatibilities
SCIENTIFIC NOTE
Nmf pca deficiency: in dry and atopic skin, pca levels are 20-40% lower than healthy controls. the mechanism: reduced filaggrin expression (common flg gene mutation in eczema) produces less pca precursor. topical pca replenishment directly compensates for this filaggrin-pathway deficit.
Last Verified: 2026-03-22
Primary Sources: Cosing database,arginine pca nmf pca humectant review