Ingredient Guide

Arginine

Also known as: Arginine, L-Arginine, L-Arginine HCl

All skin types

What It Is

An amino acid naturally found in skin as part of the Natural Moisturizing Factor (NMF). Used in skincare as a humectant, pH adjuster, and hair/skin conditioning agent.

What It Does

Attracts moisture to the skin as part of the NMF amino acid complex. In some formulas also acts as a pH adjuster (slightly alkaline).

Best For

NMF hydration supportHair conditioning

Benefits

  • Skin-identical — part of the NMF amino acid system
  • Humectant that supports moisture retention
  • In hair products: helps smooth the hair cuticle

When to Be Careful

  • No notable concerns at typical cosmetic concentrations

Commonly Found In

NMF moisturizersExfoliating tonersHair serumsScalp treatments

FAQs About Arginine

What does arginine do in skincare?
As one of the amino acids in skin's Natural Moisturizing Factor, arginine helps attract and retain moisture. In some formulas it also adjusts pH due to its basic nature.