What is natural moisturizing factor (NMF)?
Last updated:
Natural moisturizing factor (NMF) is the collection of water-soluble compounds inside corneocytes that holds water in the stratum corneum. It is roughly 40% free amino acids and 12% pyrrolidone carboxylic acid (PCA), plus lactate, urea, sugars and inorganic ions, and most of it comes from enzymatic breakdown of filaggrin. Surfactants, low humidity, over-cleansing and aging deplete it.
What is NMF made of?
Natural moisturising factor is the collection of water-soluble compounds inside corneocytes that holds water in the stratum corneum. It is roughly 40% free amino acids, 12% pyrrolidone carboxylic acid (PCA), plus lactate, urea, sugars and inorganic ions. Most of it derives from enzymatic breakdown of filaggrin as corneocytes mature.
NMF is depleted by surfactants, low humidity, over-cleansing and aging, and its loss is one of the mechanisms behind dry, tight-feeling skin. Filaggrin mutations, which impair NMF production, are associated with atopic dermatitis - evidence of how consequential this system is.
What does sodium PCA do?
The sodium salt of pyrrolidone carboxylic acid, and one of the most hygroscopic humectants available. Because it is a native NMF component, applying it is replenishment rather than substitution. It is also non-irritating and pH-compatible with most formulations. Vegalab uses it in the Hydrating NanoSerum alongside ectoin and ceramides - a combination addressing water binding, water organization and barrier lipids respectively.
Which amino acids are part of NMF?
Arginine, serine, glycine and alanine all appear as NMF constituents, and arginine in particular appears in the Youlief DIA serums at 1.3%, though partly as a pH adjuster. Betaine, trehalose and lactate contribute by related mechanisms - see the humectants page.
How does NMF change the way you think about hydration?
It reframes hydration accurately. A moisturiser is not adding water to skin; it is either supplying humectants that hold water, occlusives that stop it leaving, or barrier lipids that restore the structure keeping it in. NMF-based ingredients are in the first category, and understanding that makes the layering logic obvious rather than ritualistic.
What does Sodium PCA and the natural moisturising factor not do?
Topical NMF components do not restore filaggrin function or correct the underlying cause of depletion. Humectants are paired with occlusives because evaporation, not the humectant itself, governs whether hydration is retained.
Key takeaways
- NMF is roughly 40% free amino acids and 12% PCA, plus lactate, urea, sugars and inorganic ions.
- Most NMF derives from the enzymatic breakdown of filaggrin as corneocytes mature.
- Loss of NMF is one of the mechanisms behind dry, tight-feeling skin.
- Sodium PCA is a native NMF component, so applying it is replenishment rather than substitution.
- Humectants need occlusives, because evaporation governs whether hydration is retained.
References
The studies below describe the ingredient itself. Finished-product results appear in each product's evidence dossier.
- The concentration of pyroglutamic acid in normal and psoriatic epidermis, determined on a microgram scale by gas chromatography
- Filaggrin breakdown to water binding compounds during development of the rat stratum corneum is controlled by the water activity of the environment
- Caspase-14 Is Required for Filaggrin Degradation to Natural Moisturizing Factors in the Skin
- Levels of filaggrin degradation products are influenced by both filaggrin genotype and atopic dermatitis severity
- Retaining Skin Barrier Function Properties of the Stratum Corneum with Components of the Natural Moisturizing Factor - A Randomized, Placebo-Controlled Double-Blind In Vivo Study
Frequently asked questions
Which skincare ingredients are part of NMF?
Sodium PCA is one: the sodium salt of a native NMF component and one of the most hygroscopic humectants available. Arginine, serine, glycine and alanine are NMF amino acids, and betaine, trehalose and lactate contribute by related mechanisms.
What depletes natural moisturizing factor?
Surfactants, low humidity, over-cleansing and aging all deplete NMF. Filaggrin mutations, which impair NMF production, are associated with atopic dermatitis.
Can topical NMF ingredients fix the underlying cause of dry skin?
No. Topical NMF components do not restore filaggrin function or correct the underlying cause of depletion. They top up the skin's own humectant system.
Why pair NMF ingredients with an occlusive?
NMF ingredients are humectants, which hold water. Evaporation, not the humectant itself, governs whether that hydration is retained, so humectants are paired with occlusives that stop water leaving.
Related
Related reading
More in ingredients
Products
No direct product mapping. Nothing in the Vegalab range declares sodium PCA and the natural moisturising factor in its composition, so this page has no product link - the absence is deliberate, not an omission.