Isostearoyl Hydrolyzed Silk
What is Isostearoyl Hydrolyzed Silk?
Isostearoyl Hydrolyzed Silk originates from silk proteins extracted from Bombyx mori silkworm cocoons. The process involves hydrolyzing the fibroin protein into smaller peptides via enzymatic or acid breakdown, enhancing solubility. These peptides are then esterified with isostearic acid, a branched saturated C18 fatty acid from vegetable or animal sources, creating an oil-soluble derivative. This modification shifts it from water-soluble to lipophilic, improving compatibility with oil-based formulations. Classified as a skin conditioning agent in cosmetics, it functions by depositing on the skin's surface to form a breathable film. This film mimics the skin's natural lipid barrier, aiding moisture retention, reducing transepidermal water loss, and imparting a smooth, supple texture. Typically incorporated into emulsions like creams, lotions, and serums at low levels for enhanced sensory feel and conditioning effects without greasiness.
Roles in Formulation
This ingredient serves the following purposes in cosmetic formulations:
Benefits
Supports skin hydration by forming a moisture-locking film.
Enhances skin texture for a smoother, softer feel.
Contributes to product spreadability and non-greasy finish.
Who It's For
A quick guide for who this ingredient may suit (and who should be cautious).
| Who May Benefit | Who Should Avoid |
|---|---|
| People with dry or dehydrated skin seeking conditioning. | Persons with allergies to silk proteins. |
| Individuals using emollient-rich moisturizers or creams. | Vegans avoiding animal-derived ingredients. |
| Those desiring improved skin suppleness from natural-derived actives. | Individuals sensitive to protein hydrolysates. |
Safety Notes
- Deemed safe for cosmetic use by ingredient safety reviews.
- Presents low risk of comedogenicity or pore clogging.
Frequently Asked Questions about Isostearoyl Hydrolyzed Silk
What makes Isostearoyl Hydrolyzed Silk different from regular hydrolyzed silk?
The isostearoyl modification adds fatty acid chains, making it oil-soluble for better use in emulsions compared to water-soluble hydrolyzed silk.
Is it safe for everyday skincare products?
Yes, it's regarded as safe in cosmetics with a low hazard profile from authoritative reviews.
What skin types does it suit best?
It works well for dry skin needing conditioning and moisture barrier support.