On This Page

• What Is the Natural Moisturizing Factor?
• Why No One Talks About the Most Important Moisture System in Skin
• Why Amino Acids Are the Core of NMF
• How Depleted NMF Leads to Dry Skin and Flaky Skin
• How Depleted NMF Can Also Lead to Oily Skin
• Why Typical Moisturizers Don’t Truly Hydrate Skin
• Comparison Chart: Low vs Healthy Amino Acid Content
• How Hydration Actually Breaks Down
• How to Support and Restore NMF
• Related Topics
• FAQ
• References

What Is the Natural Moisturizing Factor (NMF)?

The Natural Moisturizing Factor, or NMF, is a collection of water-soluble, low-molecular-weight compounds inside the outermost layer of your skin, the stratum corneum. Its job is to help the skin attract water, bind water, and hold onto water, which is essential for a smooth, flexible, hydrated skin surface.[1]

The NMF is made up of multiple compounds that skin naturally uses to regulate moisture, including:

• amino acids
• PCA and sodium PCA
• urea
• lactates
• other naturally occurring hygroscopic molecules

Of these, amino acids are one of the major components and are central to the NMF story.[1] This matters because when amino acid-related moisture support is low, skin loses some of its ability to stay comfortably hydrated.

Why No One Talks About the Most Important Moisture System in Skin

This is one of the strangest things in skincare: the conversation around “hydration” is everywhere, but the conversation around the skin’s own built-in water-retention system is almost nowhere.

Most skincare marketing reduces hydration to a product category. It teaches people to think in terms of creams, gels, serums, and rich textures. But the deeper question is almost never asked:

The answer is not just “because you put moisturizer on it.” Skin appears hydrated when the outer layer has enough water and enough water-binding material to keep that water from disappearing too quickly. That is where the NMF becomes so important.[1]

In other words, if you only think about hydration as something you apply, you miss the more important question of whether skin is able to retain water once it is there.

Why Amino Acids Are the Core of NMF

Amino acids are not just another ingredient category in skincare. They are part of the skin’s own moisture system. Research on NMF consistently identifies amino acids among the principal hygroscopic components involved in stratum corneum hydration and function.[1]

This is a major reason amino acids matter so much in skin science. They are not merely surface beautifiers. They help explain why skin can feel naturally soft, smooth, and hydrated when the moisture system is functioning properly.

When amino acid-related NMF support is healthy, skin is better able to:

• hold water in the stratum corneum
• stay flexible instead of brittle or tight
• shed dead cells more normally
• look less flaky and less rough
• maintain a smoother-looking surface

This is why AminoGenesis is so focused on amino acids. They are not peripheral to hydration. They are part of hydration biology.

How Depleted NMF Leads to Dry Skin, Flaky Skin, Rough Texture, and Eczema-Prone Skin

When NMF levels are depleted, the outer skin layer loses some of its ability to bind and retain water. That makes the surface drier and less flexible, and it can disrupt normal skin comfort and appearance.[1]

This often shows up as:

• dry skin that feels tight or uncomfortable
• flaky skin that sheds unevenly or becomes patchy
• rough texture that no longer feels soft
• dull skin that loses its healthy-looking surface
• fine dehydration lines that can exaggerate the appearance of aging

NMF is also relevant to eczema-prone skin and atopic dermatitis-related dryness because dry, scaly, barrier-stressed skin is closely tied to altered moisture handling in the stratum corneum.[5]

In simple terms, skin with low NMF is less able to stay comfortably hydrated. It dries out more easily, flakes more easily, and looks less healthy even if product is applied on top.

How Depleted NMF Can Also Lead to Oily Skin

One of the most misunderstood hydration problems in skincare is oily but dehydrated skin.

Many people assume that if skin looks shiny, it must be well moisturized. But oil and water are not the same thing. Sebum can coat the surface while the stratum corneum is still lacking the water-binding compounds needed for true hydration.

This can create a confusing skin state:

• skin looks oily yet still feels tight
• the T-zone becomes shiny while cheeks feel dry
• breakout-prone skin still flakes around the nose or mouth
• skin seems greasy but never fully comfortable

In this situation, the problem may not be “too much moisture.” It may be that the skin is producing oil while still lacking enough internal water retention. Depleted NMF helps explain why skin can look oily on the surface but remain dehydrated underneath.

Why Typical Moisturizers Don’t Truly Hydrate Skin

This is where many skincare routines fall short.

Most conventional moisturizers help in one of three ways:

• occlusives reduce evaporation by forming a surface film
• emollients soften and smooth the outer skin surface
• humectants help attract water

These functions can be very helpful. But many products still mainly improve how the surface feels and looks in the moment. They do not automatically rebuild the skin’s own internal hydration system.[2]

By contrast, amino acids are part of the natural water-retention machinery of the stratum corneum itself. They are tied to the skin’s ability to hold water rather than merely coating the surface.

The best hydration strategy is not surface support instead of NMF support. It is understanding that surface support works best when paired with the skin’s real water-retention biology.

Comparison Chart: Skin with Depleted Amino Acid Content vs Skin with Healthy Amino Acid Content

How Hydration Actually Breaks Down

Skin dehydration usually follows a logical chain. Once you see it this way, it becomes much easier to understand why surface-only solutions often disappoint.

Support the moisture system earlier in the chain, and the rest of the outcomes begin to improve downstream.

How to Support and Restore NMF

Supporting the NMF means helping skin do what healthy skin naturally does: hold water more effectively and stay more comfortable.

Good ways to support that process include:

• use gentle cleansing rather than aggressive stripping
• avoid over-exfoliation when skin is already dry or flaky
• support the skin barrier alongside hydration
• use formulations that recognize the role of amino acids in skin hydration
• understand that oily skin may still need hydration support

The goal is not just to make skin feel coated. The goal is to help skin behave more like healthy, hydrated skin behaves.

Common Hydration Mistakes

• assuming oil means hydration
• using richer products without addressing water retention
• over-cleansing already dry or flaky skin
• over-exfoliating barrier-stressed skin
• thinking every moisturizer works the same way

Hydration Is More Than a Moisturizer

If skin cannot hold water well, surface softness only goes so far. Support the biology of hydration with skincare built around ingredients skin already understands.

Frequently Asked Questions

What is the Natural Moisturizing Factor in skin?

The Natural Moisturizing Factor is a group of compounds in the stratum corneum that help attract and retain water, supporting hydrated, flexible skin.[1]

Are amino acids part of NMF?

Yes. Amino acids are one of the major components of the Natural Moisturizing Factor and are strongly connected to the skin’s water-holding ability.[1]

Can low NMF cause dry skin and flaky skin?

Yes. When NMF is depleted, the skin loses some of its ability to retain water, which can contribute to dryness, flaking, tightness, and rough texture.[1]

Can skin be oily and dehydrated at the same time?

Yes. Skin can produce surface oil while still lacking enough internal water retention, which is why oily skin can still feel tight, flaky, or uncomfortable.

Do moisturizers actually hydrate skin?

Many moisturizers help soften the surface and reduce water loss, but true hydration also depends on whether the skin can retain water in the stratum corneum. That is where NMF becomes so important.[2]

References & Scientific Sources

The concepts discussed on this page are supported by published dermatology and skin science research on NMF, amino acids, moisturizers, dry skin, barrier homeostasis, and stratum corneum hydration.

1. Natural moisturizing factors (NMF) in the stratum corneum — PubMed
2. The role of moisturizers in addressing various kinds of dermatitis — NCBI / PMC
3. Moisturizers: The Slippery Road — NCBI / PMC
4. Direct quantification of natural moisturizing factors in stratum corneum — NCBI / PMC
5. American Academy of Dermatology: Atopic dermatitis symptoms and dry, itchy skin
6. DermNet: Emollients and moisturisers