What it is
In the register’s words: “Protein hydrolyzates, silk.”
- EU register name (INCI)
- HYDROLYZED SILK
- CAS number
- 96690-41-4
- EC number
- 306-235-8
What the register lists it for
These are the uses the European Commission’s CosIng register lists for Hydrolyzed Silk in any cosmetic, hair roles first. They say why a maker might add it, not what it does in one formula, and they aren’t a safety rating.
- Hair conditioning
-
The register’s hair role for ingredients that make hair feel softer, smoother or easier to comb. Most conditioners, masks and leave-ins list several.
Register definition: “Enhancing the appearance and feel of hair. Leaving the hair easy to comb, supple, soft and shiny and/or imparting volume, lightness, gloss, texture, etc.”
- Antistatic
-
Cuts the static that makes dry hair fly away. Many conditioning ingredients carry this role too, because both work at the hair’s surface.
Register definition: “Preventing and/or reducing static electricity by neutralising electrical charge on surfaces.”
- Humectant
-
Holds water in the product and on the surface it touches. Glycerin, honey and aloe are common humectants on curly-hair labels.
Register definition: “Retaining and/or preserving the moisture in a product during use.”
- Skin conditioning
-
The register’s broad role for ingredients that keep skin in good condition. On a hair label it often sits beside a hair role, or marks a plant oil or extract.
Register definition: “Maintaining the skin in good condition.”
Where it sits on each label
US labels list ingredients from most to least, except that those at 1% or less may follow in any order. A name near the top is a large part of the formula. A label doesn’t mark where the 1% point falls, so further down, the order says little about how much is in it.
- Deep conditioners 1 label First five names: 0 of 1 Deep conditioners without it
- Stylers 2 labels First five names: 0 of 2 Stylers without it
- Heat protectants 1 label First five names: 1 of 1 Heat protectants without it
Every label, product by product (4)
- Kristin Ess Strand Strengthening Reconstructive Moisture Mask Deep conditioner 22nd of 50 names
- PATTERN Curl Gel Styler 9th of 38 names
- SheaMoisture Coconut & Hibiscus Curl Enhancing Smoothie Styler 18th of 25 names
- TRESemmé Protecting Heat Styling Spray Heat protectant 4th of 29 names
Each line runs from the first name on a label to the last; a dot is where this ingredient sits. Makers change formulas now and then; if the list on your bottle differs, go by your bottle.
Your next step
Other hair conditioning ingredients on these labels
- Glycerin 131 labels
- Panthenol 72 labels
- Cocos Nucifera (Coconut) Oil 69 labels
- Behentrimonium Methosulfate 38 labels
- Caprylyl Glycol 37 labels
- Behentrimonium Chloride 34 labels
- Cocamidopropyl Betaine 34 labels
- Simmondsia Chinensis (Jojoba) Seed Oil 34 labels
Updated · The name, numbers and uses come from the European Commission’s CosIng entry (CC BY 4.0); we write the uses in US spelling and put the hair ones first. The labels are each maker’s own. The order rule is the FDA’s Cosmetics Labeling Guide. All our sources are on the Sources page.