What is it? Silk is made by silkworms and obtained from those silkworm cocoons. It can be hydrolyzed to make it water-soluble so it can easily be incorporated into our skincare products and cosmetics.
INCI Hydrolyzed silk
Appearance A slightly granular white to off-white powder or a liquid.
Usage rate 2–5%
Scent It varies greatly with suppliers. Mine has a slight sweet smell that does not carry through to finished products at all, but I’ve heard from readers who have purchased it from other suppliers and the scent is unpleasant and powerful enough to overwhelm products at low usage rates.
pH 5–7
Solubility Hydrolyzed silk is water soluble; if the silk has not been hydrolyzed it will not dissolve, so make sure you’re purchasing hydrolyzed silk!
Why do we use it in formulations? Silk is an excellent moisturizing ingredient with heaps of label appeal (a lotion with silk? How luxurious!). It creates a very fine film over the skin, helping create a smoother appearance and reduce trans-epidermal water loss. Silk also helps protect hair.
Do you need it? No, but I adore it and use it frequently.
Refined or unrefined? Ensure whatever you purchased has been hydrolyzed; Tussah silk will not work, nor will plain powdered silk.
Strengths Excellent moisturizing ingredient, reduces water loss, higher molecular weights can add some smoothing and sheen to skin and hair.
Weaknesses It isn’t vegan, and it can stink.
Alternatives & Substitutions A different hydrolyzed protein would be the best substitution for hydrolyzed silk. Try oat, baobab, quinoa, rice, or oat, making sure you’re paying attention to which phase your substitution goes into (heated or cool down).

If you have a different type of silk that will work too, as long as it has also been hydrolyzed. I typically specify “hydrolyzed silk” in my recipes as the water-soluble part is more important than the particle size (learn more about that in the Tips, Tricks, and Quirks section below).

How to Work with It Include it in the heated water phase; it can also be cold-processed if needed.
Storage & Shelf Life Stored somewhere cool, dark, and dry, hydrolyzed silk should last about two years.
Tips, Tricks, and Quirks It is often possible to purchase hydrolyzed silk in a variety of particle sizes—powder, peptides, and amino acids. The powder is usually the largest particle size, followed by peptides and then amino acids. The finer the powder the more readily it can penetrate the skin and hair, but there will be less of a visual sheen/finish. I use peptides to get the best of both worlds.
Recommended starter amount 30g (1oz)
Where to Buy it  Buy it from an online DIY ingredient supplier or Amazon. Mine is from New Directions Aromatics.

Some Formulations that Use Silk


Posted on

January 11, 2019