Natural Moisturizing Factor (NMF): What It Is and How to Maintain Skin Hydration

The Natural Moisturizing Factor (NMF) is a complex of organic molecules present in the epidermis that are responsible for retaining moisture in the skin. NMF consists of:

• Amino acids (40%) – key components for maintaining the hydro-lipid balance;
• Sodium pyrrolidone carboxylate (PCA) (12%) – binds moisture and strengthens the skin barrier;
• Urea (7%) – provides humectant and keratolytic properties;
• Glycerol and organic compounds (17%) – attract water molecules;
• Minerals (magnesium, potassium, calcium, sodium – 12%) – regulate cellular processes;
• Lactic and citric acids, chloride and phosphate ions (12%) – maintain skin pH.

The Role of NMF in Skin Health

Disruption of NMF balance leads to dehydration, loss of elasticity, and skin flaking. The protein filaggrin plays a critical role in NMF formation, as it breaks down into amino acids and other NMF components.

Functions of Filaggrin:

✅ Forms cross-links between corneocytes, strengthening the skin barrier.
✅ Generates NMF, maintaining optimal hydration levels.
✅ Regulates gene activity involved in UV protection and calcium metabolism.
✅ Maintains the acidic pH of the stratum corneum, crucial for skin microbiota.
✅ Influences ceramide synthesis, ensuring proper lipid composition (ceramides, cholesterol, fatty acids).

Causes of Dry Skin and Genetic Factors

A primary cause of dryness is mutations in the FLG gene, which encodes filaggrin. This results in:

• Transepidermal water loss (TEWL);
• Impaired skin barrier function;
• Increased risk of atopic dermatitis.

🔹 Did you know? FLG mutations occur in 10% of Caucasians, explaining the high prevalence of dry skin in this population.

How to Restore NMF?

For genetically predisposed dry skin, replacement therapy is effective, including:

• Humectants (urea, glycerol, hyaluronic acid);
• Emollients to repair the lipid barrier;
• Probiotics to support skin microbiome balance.

Conclusion

NMF is essential for skin hydration. Its deficiency causes dryness, irritation, and dermatological conditions. To maintain NMF balance, use hydrating and reparative skincare, especially for genetic xerosis.