INCI Name: Sodium PCA
Appearance: Clear to pale yellow liquid
Solubility: Water-soluble
Usage Rate: 0.2% – 6%
Function: Humectant, moisturizer, hydration booster, skin/hair conditioner
Sodium PCA is a naturally occurring humectant derived from amino acids, and is one of the key components of the skin’s Natural Moisturizing Factor (NMF). It attracts and retains moisture, improves skin texture, and enhances the feel and performance of personal care formulations for both skin and hair.
Sodium PCA (pyrrolidone carboxylic acid salt) is a highly effective humectant that binds moisture to the skin and hair. It’s derived from L-glutamic acid and is known for its high moisture-retention capacity. Because it is a natural component of healthy skin, it is especially gentle and non-irritating—even for sensitive skin types.
Add Sodium PCA to the water phase at room or warm temperatures (below 60°C). Use in combination with other humectants for long-lasting hydration synergy.
While Hyaluronic Acid attracts and holds water mostly at the skin’s surface, Sodium PCA penetrates more readily and mimics the skin’s own natural moisturizing factors (NMF). It provides a lighter, non-sticky hydration, ideal for oily skin or leave-on products where HA can feel tacky.
It naturally occurs in human skin as part of the NMF complex, which maintains hydration and barrier function. Adding it back into formulations reinforces what the skin already uses to stay supple.
Yes, at higher percentages (>5%), its strong hygroscopicity can thin gels or cause viscosity shifts. It’s usually balanced with film-forming humectants like Glycerin or Hydroxyethyl Urea for more stable textures.
It’s an excellent moisture balancer for hair. It reduces static, improves elasticity, and prevents brittleness, especially in damaged or chemically treated hair.
Not entirely. Sodium PCA is more hygroscopic and less sticky than Glycerin, but it’s usually used with Glycerin or other humectants. A multi-humectant system gives longer-lasting hydration and prevents the formula from feeling overly tight or tacky.
Yes. It’s derived from glutamic acid (an amino acid sourced from plants). It’s considered safe, non-irritating, and compatible with natural/green beauty positioning.
It can be sensitive in very acidic systems (pH < 4), where it may hydrolyze over time. It’s best kept in pH ranges of 4.5–7.0.
By replenishing NMF components, it helps reduce transepidermal water loss (TEWL) and improves stratum corneum flexibility. This makes it synergistic with ceramides, panthenol, and fatty acids in barrier creams or recovery serums.
Yes. By enhancing hydration and reducing TEWL, Sodium PCA keeps the stratum corneum plump and permeable, which can improve the bioavailability of water-soluble actives.
It adapts well to both. In humid conditions, its hygroscopic nature prevents water loss from the skin into the air. In dry climates, it draws water from deeper layers of the skin but needs to be paired with occlusives (e.g., oils, butters, ceramides) to prevent dehydration.
Indirectly, yes. By reinforcing the NMF system, it strengthens the barrier, which makes skin less prone to irritation from acids, retinoids, or surfactants.
