Silk has been valued throughout the world for its extraordinary beauty and unique qualities. For millennia, humans have been drawn to the fabric, the deservedly named ‘Queen of Fabrics’ for both its luxury and its comfort in all temperatures.

Slowly, we are learning more and more about this wonder of the world; this natural miracle. And now, this unique material is revealing its secrets about skincare.

Our skin is our largest organ and is our physical barrier - our first line of defence against environmental stress and Silk has been scientifically proven to benefit our skin in numerous ways. 

Silk is biocompatible with human skin and tissue and the scientific world has known about this for centuries. 

There is solid research showing that Silk in skincare reduces the appearance of fine lines, helps with hydration levels, improves elasticity, fights pollution and increases the rate of cellular regeneration. 

But first….a short history of Silk.

The History of Silk

Ancient legend has it that the Empress Leizu was enjoying a cup of tea under a mulberry tree one day in the 27th Century BC, when a cocoon fell into her tea. As she went to pick it up, she found that she could unravel it. She was so taken by its shimmering beauty that she began to cultivate silkworms and invented the first silk loom and the art of sericulture. (the production of Silk)

Recent archaeological discoveries have found silk filaments in tombs dating back to 8,500 years. It is fascinating to think that primitive womankind (and mankind) was as drawn to Silk 8,500 years ago as we are today. I truly believe that we are attracted to it on a very primal and subconscious level.

Silk exerted such power over people that it was responsible for the opening up of trade routes between East and West; the Silk roads. 

What Is Silk Made From?

Silk is a protein fibre (as opposed to a cellulose fibre) which most commonly comes from the Bombyx Mori silkworm, a type of moth. 

Other species of silkworms also produce silk, as do spiders, but most silk worldwide comes from the Bombyx Mori. 

All proteins are made up of chains of amino acids, and this is where it gets really exciting for silk in skincare. 

The Protein Structure of Silk 

The structure of Silk is so similar to human skin that we have 18 amino acids in common with Silk. To put this into context, there are only 20 amino acids in the human body. This means we share 90% of our amino acids with those found in Silk. 

This may go some of the way towards explaining why we have been drawn to and captivated by Silk for 8,500 years. On a primal and physical level, our bodies instinctively know that Silk is something we can relate to. 

The Two types of Silk Protein

Silk, a protein fibre, is made up of two different types of protein; Silk Fibroin and Silk Sericin. Each has overlapping but differing properties and each is made up of different amino acids.

Silk Fibroin

Silk Fibroin is a protein which makes up the filaments of Silk. Fibroin accounts for most of the Silk protein - typically between 72 - 81% by weight. Silk Fibroin is the ‘inner core’ of the Silk, the ‘building block’ of Silk, and gives Silk its famed substance and strength. 

The Benefits of Silk Fibroin

Silk Fibroin stimulates the skin to synthesise collagen protein, thereby improving the ‘bounce’ and elasticity of skin. 

Silk Fibroin accelerates the rate of cellular regeneration of the skin. In other words, it speeds up the renewal process and helps with healing and scarring. 

It mimics our skin’s ‘Natural Moisturising Factor’ (NMF), increasing hydration levels in our skin and simultaneously reduces ‘Trans-Epidermal Water Loss’ (TEWL).

It protects our skin against the ravaging and ageing effects of pollution, mopping up free radicals with its antioxidant action.

Silk Fibroin is mainly used in skincare, though you will see Silk Sericin used too. 

Silk Sericin

Silk Sericin is the secondary protein of Silk and accounts for between 19 - 28% of the Silk by weight. It is the ‘glue’ which binds the silk filaments into the shape of a cocoon. 

Silk Sericin also has wound-healing and anti-ageing,moisturising, hydrating and skin-repairing properties but it is also used in haircare products, due to its natural affinity with keratin. (Keratin is a building block of our hair and nails.)

It is also known for its ability to bind to and repair damaged hair, using its ‘glue’ function in much the same way it does in the cocoon.

Silk Sericin is also used in medical applications, because of its ability to accelerate wound healing. 

Silk Amino Acids

All proteins are made up of amino acids, and although Silk is made up of 18 amino acids, 3 of them steal most of the limelight. The main ones are Alanine, Glycine and Serine.

It is important to note that these amino acids act in synthesis; they work together, and the most studied are Alanine and Glycine.

Alanine:

In skincare, alanine is a conditioning and hydrating agent which is known to reduce epidermal water loss. This amino acid is small enough to penetrate the skin barrier.

 

Alanine is mainly found in Silk Fibroin. 

Glycine:

Glycine is known to improve the visible signs of ageing by increasing water retention and stimulating the production of collagen.

Glycine is mainly found in Silk Fibroin. 

Serine:

Serine consists of ‘natural moisturising factors’ and keratin and is known to have significant moisturising effects. 

Serine is mainly found in Silk Sericin. 

10 Scientifically Proven Benefits of Silk Proteins for Skin

1. Silk proteins have a visible effect on fine lines and crows feet, and therefore have anti-ageing effects.
2. Silk has powerful, antioxidative stress properties and studies have shown that it is particularly effective against pollution. 
3. Silk improves the look and feel of our skin.
4. Silk stimulates the production of our body’s own collagen protein, thereby improving skin elasticity. Skin elasticity decreases as we age, and Silk helps to offset this mechanism.
5. Silk is biocompatible with our skin. We have 90% of our amino acids in common with Silk proteins. This high level of affinity means that skin responds well to Silk.
6. Silk alleviates damage caused by the sun to our skin. Sun damage adversely affects skin elasticity, hydration levels and can cause hyperpigmentation. Hyperpigmentation is caused by excess melanin, and melanin is formed by the oxidation of tyrosinase. Silk works to inhibit tyrosinase, and thereby reduces hyperpigmentation. 
7. Silk promotes cellular regeneration, helping with renewal and a brighter complexion. 
8. In addition to containing beneficial amino acids, Silk also contains trace amounts of copper. Copper has powerful anti-viral, antimicrobial and anti-ageing effects.
9. Silk is hypoallergenic and can be tolerated by many people, including those with sensitive skin. 
10. Silk acts to form a film on skin which not only protects against pollution but also helps to rebalance the natural skin microbiome, which has been shown to be disrupted by airborne particulate pollution. Particulate pollution has been shown to accelerate the skin’s ageing process.

The Different Types of Silk Proteins

You will see different types of Silk ingredients on skincare and cosmetic formulations. The main differences between them are the way in which Silk has been extracted, and which formulations they can be used in. 

The different Silk products have different particle sizes, and the smaller the particle, the more likely it is that the Silk can penetrate the skin barrier. Silk benefits the skin whether sitting on top of the skin, or whether it is absorbed through the skin, depending on the function it performs in any given formulation. 

You may see ‘Hydrolyzed Silk’, ‘Silk Powder’, ‘Silk Amino Acids’ and ‘Silk Peptides’ on cosmetic ingredient lists, but they all contain Silk.

Silk - A Very Sustainable, Renewable Ingredient

We should all try and use ingredients which are as kind to the Earth as they are to our skin, and in this respect, Silk scores very highly indeed.

Sericulture (the production of Silk) requires vast numbers of mulberry trees to be planted. Mulberry trees are particularly beneficial for the environment because of the highly diverse plant and animal life they support around them. 

So many of these trees are needed that the production of Silk results in more carbon being removed than being made. The production of Silk is a carbon sink. 

In addition to that, Silk is a biodegradable and compostable, renewable resource which nourishes the soil as it decomposes. 

Here at This Is Silk, we believe that Silk is the most potent skincare ingredient we are aware of, which benefits the skin in so many different ways.