The skin’s NMF: our very own moisturising mechanism & how it works

Here we explore the skins Natural Moisturising Factor in a bit more detail (spoiler: our bodies are amazing)

The skin’s NMF: our very own moisturising mechanism & how it works

Ever wondered why kids have such great skin, without needing a Korean 10 step routine to keep them in check? Well - our skin is actually pretty awesome at regulating healthy skin functioning without any real need for us to get involved (I am talking pre-hormones…)

This week I wanted to delve a bit deeper into the skin’s own moisture mechanism, known as its ‘Natural Moisturising Factor’ or NMF. This is a very appropriate name for it, as it basically is designed to keep our skin hydrated.

 

First things first: why is hydrated skin good?

Other than achieving a lovely glow, hydration is also key to healthy skin functioning. If our skin becomes dehydrated, tiny cracks form in the skin’s surface, which results in an impaired barrier function. Our skin barrier is the first line of defence against microbes, UV rays & water loss. If the barrier function is compromised, it means that more water is likely to evaporate from the skin surface via trans-epidermal water loss (TEWL), leading to further dehydration. It also means our body's defenses against unwanted bacteria is compromised, meaning we may get ill or infections more easily. 

 

So What is the NMF and what does it do?

The NMF is a substance produced naturally by the epidermis, to coat the stratum corneum (the very outer layer of the epidermis that is exposed to the elements). It is comprised of amino acids (the building blocks of peptides/proteins), humectants (urea, sodium hyaluronate), minerals (sodium, magnesium, potassium, calcium, phosphate, chloride), sugars & lactate. This delicately balanced cocktail of ingredients work together to draw moisture to the skin and support the skin barrier to prevent excess water loss via TEWL. 

The NMF also plays a role in supporting the skin’s acid mantle - a naturally acidic coating (pH 4.5-6) on the surface of the skin. The low pH gives a hostile environment for bacteria, so helps to kill off harmful substances before they can make us ill. The acid mantle is formed when the NMF mixes with sebum (the skin’s natural oils) and our sweat, so is an incredibly delicate and complex bodily process that we often take for granted but is hard at work daily to keep us healthy. 

 

What happens if the production of our NMF is disrupted?

As the NMF is a coating on top of the skin, there are some external factors which can interfere with it, causing an imbalance. A common example is using strong surfactants regularly. Surfactants (short for surface-active-agents) are molecules with a water-loving head (usually derived from a sugar), and a long-chain oil-loving tail (derived from either natural or synthetic oil sources). 

Their ability to dissolve their lipophilic tails in oil (which is how they remove excess oil from our skin) also means that using frequently can strip our skin of its natural lipids. The good news is that our skin is excellent at bringing itself back into balance (praise homeostasis), but if your skin is already on the dry side, then the barrier is likely already compromised, making further surfactant use more disruptive than the last (as surfactants are able to penetrate into the skin further). 

Just think about our healthcare workers, who are washing their hands constantly throughout the day (no doubt with strong cleansing agents) in addition to working in environments where they need their defenses to be strongest. Shout out to those in the NHS looking after us on mass, and to one brand in particular who is looking to care for these hard working hands, Nursem.

 

So how can we protect our NMF?

The good news is that this stuff is created naturally, via the recycling of a protein called filaggrin, which binds the corneocytes (skin cells). So as the new skin cells grow at the base of the epidermis, and older dead cells are shed at the top, their binding proteins are then recycled to create this coating to protect the skin. All this going on whilst we go about our business! 

So to protect your NMF, you essentially just need to not do anything too disruptive to the skin. 

Things that would be considered disruptive to the skin:

  • Use of alcohol (hand sanitizer etc)
  • Over-use of resurfacing acids (AHA/BHA etc)
  • Over-use of strong surfactants

If you do use any of the above, you will probably notice your skin becoming dry, red and perhaps flaky. To counteract this, you need to be aware of how to support the skin barrier and in turn, regulate the production of the NMF. 

It has been shown that topical application of barrier-supporting ingredients can help to support the skin’s natural NMF so look for products to include:

  • NMF-mimicking ingredients (lactate, amino acids, minerals)
  • Sebum-mimicking occlusives (squalane, jojoba oil etc)
  • Ceramides (to support healthy binding of the skin cells)
  • Humectants (glycerin, urea, sodium hyaluronate)

 

Our picks of skin-supporting products:

Beauty Pie Superactive Capsules Essential Ceramides+ - A rich serum/oil with glycolipids & sphingolipids, which support the skins natural ceramide production 

The Ordinary Natural Moisturising Factors + HA - a thick but fast-absorbing cream containing lots of NMF-boosting ingredients such as amino acids, sodium lactate, urea & hyaluronic acid to support healthy skin functioning. 

Dr Jart+ Ceramidin Cream - a nourishing cream containing 5 types of ceramides (Ceramides NP, AP, AS, NS & AOP), alongside a host of plant antioxidants, this is a great daily option for dry skin 

CeraVe Moisturising Cream - a rich, nourishing cream containing 3 ceramides (Ceramide 3, 6-II & 1), in a simple fragrance-free emollient base. Great for those with more reactive skin.