What Is Perfluorononylethyl Stearyl Dimethicone?
Perfluorononylethyl Stearyl Dimethicone is a lab-made silicone that has been modified with a short fluorocarbon chain and a long fatty chain called stearyl. This blend of silicone, fluorine and fatty acid gives the ingredient a unique mix of slippery feel, water and oil resistance and a soft finish on skin. It does not occur in nature; chemists create it through a series of reactions that attach the perfluorononylethyl group and the stearyl group to a dimethicone backbone inside controlled reactors.
Fluorinated silicones first gained attention in the early 2000s when cosmetic labs wanted lightweight textures that could stand up to sweat and humidity without feeling greasy. Since then this ingredient has shown up in many long-wear beauty products. You will often find it in primers, foundations, tinted moisturizers, setting sprays, liquid lipsticks, sunscreens, anti-aging serums, sheet masks, leave-on hair treatments and even some waterproof mascaras. Its ability to form an even film that repels water makes it useful wherever brands promise all-day wear or a smooth blurred look.
Perfluorononylethyl Stearyl Dimethicone’s Cosmetic Benefits/Uses
This ingredient pulls its weight in formulas through two main roles
- Film forming – It spreads into a thin flexible layer that helps lock makeup in place, boosts water resistance and reduces transfer onto clothes or masks. The film also smooths over fine lines so skin looks more even
- Skin conditioning – The silky coating cuts down on rough texture, adds slip for easy application and leaves a soft almost powdery finish that many people enjoy in primers and serums
This silicone suits most skin types including normal, dry and combination because it sits on the surface rather than soaking in and helps cut down water loss. Oily and acne prone users can usually wear it too since it feels light and non greasy, though very congestion prone skin may prefer to patch test first because any film former can sometimes trap oil underneath.
The ingredient is made entirely in a lab from mineral based raw materials, not animal derived ones, so it is considered suitable for vegans and vegetarians.
No reports link it to problems during pregnancy or while breastfeeding. Still, this is not medical advice and anyone who is pregnant or nursing should have their doctor review new products to be safe.
Perfluorononylethyl Stearyl Dimethicone does not make skin more sensitive to sunlight and can even improve the wear of daily sunscreen by helping it stay put. It also plays well with most other cosmetic ingredients since it is chemically inert.
Potential Side Effects/Adverse Reactions
Reactions to topical Perfluorononylethyl Stearyl Dimethicone differ from person to person. The issues listed below are only potential outcomes and are unlikely for the average user when the ingredient is used correctly in a finished formula.
- Mild clogged pores or breakouts in very acne prone skin
- Rare cases of contact dermatitis such as redness or itching
- Temporary eye stinging if the product accidentally gets into the eyes
- Buildup on hair shafts leading to dullness if a cleansing step is skipped
If you notice irritation or any unwanted reaction stop using the product and consult a healthcare professional if symptoms persist.
Comedogenic Rating
Rating: 1 out of 5
This low score reflects how the silicone base forms a breathable surface layer while the fluorinated and stearyl groups reduce greasiness so it rarely blocks pores in standard concentrations.
It is therefore considered friendly for acne-prone and breakout-prone skin.
Remember the overall formula affects clogging potential too, so assess the full ingredient deck if congestion is a concern.
Summary
Perfluorononylethyl Stearyl Dimethicone works chiefly as a film former and skin conditioner. The silicone skeleton lays down a smooth flexible layer that boosts makeup longevity and water resistance while the fluorinated segment repels moisture and the stearyl chain leaves a soft touch finish.
Not as ubiquitous as classic dimethicone yet valued in long wear primers, transfer proof foundations and stay put lip colors it shows up most where durability and a weightless feel are must haves.
Current safety data point to a very low chance of irritation or sensitization so everyday use is generally safe for all skin types. Still, doing a quick patch test when trying any new product is a wise habit.