What Is Hydrolyzed Silk Pg-Propyl Methylsilanediol Crosspolymer?
Hydrolyzed Silk Pg-Propyl Methylsilanediol Crosspolymer is a hybrid of natural silk protein fragments and a silicone-like network. The silk part comes from raw silk fibers that are broken down with water into tiny peptides, while the Pg-propyl methylsilanediol portion is a modified silica compound that can bond to hair and skin. During manufacture, the two pieces are mixed, then “crosslinked” with hydrolyzed forms of tetraethoxysilane and C6-10 alkyl triethoxysilane. This step creates a flexible three-dimensional mesh that traps the silk peptides and lets them sit evenly on the skin or hair surface.
The ingredient was first explored in the late 1990s when formulators looked for ways to combine the softness of silk with the long-lasting feel of silicone polymers. Its popularity grew as brands sought lighter, breathable films that could smooth without weighing things down.
Today the crosspolymer shows up in rinse-off and leave-on hair conditioners, anti-frizz serums, color-protect sprays, facial moisturizers, anti-aging creams, sheet masks, hand lotions, and even lightweight primers. Its job in all these products is to form a thin protective layer that feels silky, resists humidity, and helps other actives stay put.
Hydrolyzed Silk Pg-Propyl Methylsilanediol Crosspolymer’s Cosmetic Benefits/Uses
This ingredient pulls double duty in formulas, helping both hair and skin look and feel better.
- Hair conditioning – The silk peptides cling to damaged cuticles, filling in rough spots so strands feel smoother and look shinier. The silicone network locks in moisture and creates a humidity-resistant barrier that can cut down on frizz and breakage.
- Skin conditioning – On skin the crosspolymer forms a breathable film that leaves a soft, velvety finish. It holds water close to the surface which can make fine lines appear less visible and gives lotions a luxurious glide without a greasy afterfeel.
Who Can Use Hydrolyzed Silk Pg-Propyl Methylsilanediol Crosspolymer
This crosspolymer is generally friendly to all skin types, including dry, normal, combination and oily skin, because it forms a weightless film that locks in moisture without leaving a heavy residue. Those with very sensitive or protein-allergic skin should patch-check new products since the silk peptides could trigger a rare reaction.
The ingredient is not suitable for vegans or strict vegetarians because its silk portion is sourced from silkworm cocoons. Anyone following an animal-free lifestyle may wish to choose alternative conditioning agents based on plant proteins or synthetic polymers.
Current safety data show no known issues for women who are pregnant or breastfeeding when the ingredient is used topically in cosmetics. That said, this is not medical advice. Expectant or nursing mothers should review any skincare or haircare routine with their doctor to be on the safe side.
Hydrolyzed Silk Pg-Propyl Methylsilanediol Crosspolymer does not make skin more sensitive to sunlight, so it is not considered photosensitizing. It is also color-safe for treated hair and rinses out easily with regular shampoo.
Potential Side Effects/Adverse Reactions
Responses to topical Hydrolyzed Silk Pg-Propyl Methylsilanediol Crosspolymer differ from person to person. The points below outline potential side effects, but most users will not experience them when the ingredient is properly formulated and used as directed.
- Allergic contact dermatitis – rare itching, redness or swelling in people sensitive to silk proteins
- Scalp or skin buildup – a heavy hand in leave-on products can leave a slight film that feels tacky or weighs hair down
- Follicular irritation – in very oily or acne-prone skin, residual product around hair follicles may clog pores and trigger small bumps
- Eye irritation – accidental contact may cause temporary stinging or watering
If any unwanted reaction occurs, stop using the product and seek advice from a healthcare professional or dermatologist.
Comedogenic Rating
Rating: 1/5 (low)
The crosspolymer is a large, film-forming molecule that mostly sits on the surface and does not sink deep into pores. It leaves a light, silky layer that is easy to wash off, so the risk of clogging is minimal compared with heavier oils or waxes. A rating of 1 reflects this low likelihood while acknowledging that buildup is possible if very thick leave-on products are not removed properly.
Suitable for acne-prone or breakout-prone skin in most cases.
Those using multiple silicone-based products should cleanse well at the end of the day to prevent residue stacking, which can raise the clogging potential over time.
Summary
Hydrolyzed Silk Pg-Propyl Methylsilanediol Crosspolymer conditions hair and skin by combining moisture-binding silk peptides with a flexible silicone-like mesh that smooths surfaces, seals in hydration and provides a soft, non-greasy finish. On hair it fills damaged cuticles for better shine and frizz control, while on skin it forms a breathable veil that boosts softness and makes fine lines look less obvious.
The ingredient enjoys moderate popularity, showing up most often in premium conditioners, serums and lightweight primers where a luxurious feel is desired without heavy buildup.
Current data show it is very safe for topical use with only rare reports of sensitivity. As with any new cosmetic, patch testing a small area first is a smart way to make sure your skin agrees with it.