What Is Dimethicone/Phenyl Silsesquioxane/Phenyl Bis-Silsesquioxane Crosspolymer?
Dimethicone/Phenyl Silsesquioxane/Phenyl Bis-Silsesquioxane Crosspolymer is a specialty silicone resin created by combining three silane building blocks: phenyl triethoxysilane, dimethyl dimethoxysilane and bis(trimethoxysilylethyl)benzene. These raw materials are first hydrolyzed then condensed in a solvent to form a three-dimensional network. To make the final powder feel silky and repel water the resin is surface-treated with trimethylchlorosilane or hexamethyldisilazane. The result is an ultrafine white powder that blends easily with oils or silicone fluids.
Silicone resins began showing up in color cosmetics in the 1990s when formulators looked for lighter textures that still gave long-lasting wear. This crosspolymer entered the market as a next-generation option that pairs the slip of dimethicone with the elegant finish of phenyl silicones. Today it is used worldwide in makeup and skin care that aim for a smooth soft-focus effect without a greasy afterfeel.
You will most often find this ingredient in pressed and loose powders, primer balms, liquid foundations, BB creams, matte sunscreens, oil-control lotions and certain sheet mask serums. It is prized for its ability to improve spreadability, extend wear time and leave skin with a blurred velvety look.
Dimethicone/Phenyl Silsesquioxane/Phenyl Bis-Silsesquioxane Crosspolymer’s Cosmetic Benefits/Uses
This crosspolymer serves one main purpose in a formula and its benefits stem from that role.
Absorbent: The porous silicone network soaks up excess sebum and minor perspiration helping makeup stay put and keeping skin looking fresh rather than shiny. Because it absorbs oil without drying out the skin it delivers a soft matte finish that still feels comfortable. It can also thicken thin oils giving creams and lotions a cushy cushiony texture while cutting down on greasy slip.
Who Can Use Dimethicone/Phenyl Silsesquioxane/Phenyl Bis-Silsesquioxane Crosspolymer
This powdery silicone works well for oily, combination and normal skin because it soaks up extra sebum and gives a smooth breathable finish. Dry or very dehydrated skin can still use it yet may prefer formulas that mix the ingredient with richer emollients to avoid a tight feeling. Its large molecular size and chemical stability make it gentle enough for sensitive or redness-prone skin with a low risk of stinging or flare-ups.
The material is fully synthetic with no animal-derived constituents so it fits vegan and vegetarian lifestyles. Of course final product claims depend on the brand’s overall sourcing and animal testing policies.
Topical silicones such as this crosspolymer are considered low risk for pregnant or breastfeeding women. They sit on the surface of the skin and are not expected to penetrate or reach the bloodstream. Still this is not medical advice and anyone who is pregnant or nursing should run their entire skincare routine past a qualified health professional.
Dimethicone/Phenyl Silsesquioxane/Phenyl Bis-Silsesquioxane Crosspolymer does not cause photosensitivity and will not increase the chance of sunburn. It can even help stabilize sunscreens by absorbing surface oil so the UV filters stay evenly distributed.
Potential Side Effects/Adverse Reactions
Reactions to any cosmetic ingredient vary from person to person. The points below describe possible side effects even though most people will never experience them when the ingredient is used correctly in a well-formulated product.
- Mild clogged pores or breakouts in very acne-prone skin if the product is not removed thoroughly
- Rare local irritation such as slight redness itching or dryness
- Contact allergy is extremely uncommon but could show up as a rash or swelling
- Occlusion of active treatments underneath which may amplify the strength of potent acids or retinoids leading to unexpected irritation
If any of these effects occur stop using the product and consult a healthcare professional or dermatologist for guidance.
Comedogenic Rating
Rating: 1/5 – Laboratory data and user reports show that this large silicone resin sits on top of the skin, is chemically inert and lets water vapor pass through, which keeps pores from becoming trapped under a heavy film. Because it has mild oil-absorbing properties it is even less likely than straight dimethicone to contribute to blocked pores.
Suitable for acne-prone and breakout-prone skin in most cases.
Keep in mind that a product’s full formula, your cleansing habits and other ingredients like waxes or heavy oils play a bigger role in clogging risk than this crosspolymer itself.
Summary
Dimethicone/Phenyl Silsesquioxane/Phenyl Bis-Silsesquioxane Crosspolymer is mainly an absorbent that mops up excess sebum, blurs fine lines and gives a soft matte finish. The porous silicone network locks oil inside its structure while its silky particles glide easily so creams and makeup spread smoothly and wear longer.
Though it is not a household name like plain dimethicone, formulators love it for modern lightweight primers, foundations and sunscreens so you will often spot it on ingredient lists for mid to high-end makeup.
Safety studies and decades of use point to a very low irritation or allergy risk and it does not disturb hormone activity. Still every skin is different so give any new product a small patch test first to make sure it agrees with you.