What Is Polysilicone-35?
Polysilicone-35 is a man-made silicone polymer built from repeating siloxane units that carry medium-length alkyl chains (between six and ten carbon atoms). This combination of a flexible silicone backbone and oil-loving side chains gives the material a balance of silky slip and lightweight softness that is prized in beauty formulas. The ingredient is synthesized in controlled laboratory settings by linking siloxane building blocks through a process called polymerization then grafting the alkyl groups onto the chain. Because both steps take place under strict quality controls the finished polymer is highly pure and skin friendly.
Silicones began finding their way into hair sprays and skin creams in the 1950s for their smooth touch and water-resistant finish. Polysilicone-35 is a more recent addition, developed as formulators looked for silicone ingredients that form breathable yet durable films without the heavy feel some older silicones can leave behind. Today it shows up in a wide range of products including leave-in conditioners, heat-protectant sprays, styling gels, long-wear foundations, tinted moisturizers, setting sprays, waterproof mascaras and high-SPF sunscreens.
Polysilicone-35’s Cosmetic Benefits/Uses
In formulas Polysilicone-35 delivers several practical perks that improve both product performance and user experience.
- Film forming – Creates an invisible, flexible layer on skin or hair that locks in active ingredients, boosts water resistance and helps makeup last longer
- Hair conditioning – Smooths the cuticle, reduces frizz and adds a soft, silky finish without weighing strands down making detangling easier
- Emollient – Provides a light, non-greasy softness on skin helping creams and lotions glide on effortlessly while leaving a velvety afterfeel
Who Can Use Polysilicone-35
Polysilicone-35 is gentle enough for most skin types including normal, dry, combination and oily skin. Its lightweight, breathable film does not trap excess oil so even acne-prone users usually tolerate it well. Those with very sensitive or reactive skin can also benefit because the polymer is chemically inert and fragrance free, reducing the chance of irritation.
The ingredient is synthetic and contains no animal derivatives, making it suitable for both vegetarians and vegans. Manufacturing typically follows good practice standards that exclude animal testing in many regions, though users who prioritize cruelty-free certifications should still verify a finished product’s specific claims.
Current safety data do not flag Polysilicone-35 as a risk for pregnant or breastfeeding women when used topically at the low percentages found in cosmetics. Still, this is not medical advice and anyone who is pregnant or nursing should review any skincare routine with a healthcare professional.
Polysilicone-35 does not increase photosensitivity. Because it forms a water-resistant film, it can even enhance the longevity of sunscreens but it does not replace the need for SPF.
Potential Side Effects/Adverse Reactions
Responses to any cosmetic ingredient vary from person to person. The issues listed below are possible but uncommon when Polysilicone-35 is formulated and used as intended.
- Mild skin irritation in individuals with extremely sensitive or compromised skin barriers
- Contact dermatitis if someone has a rare allergy to silicones or other formula components
- Build-up on hair with very frequent use of leave-in products which may lead to dullness until clarified
If discomfort, redness or other unwanted effects occur stop using the product and consult a healthcare professional if symptoms persist.
Comedogenic Rating
Rating: 1/5
Polysilicone-35 forms a light breathable film that sits on top of skin rather than soaking into pores, so it rarely traps oil or debris. Its large molecular size and inert nature make it unlikely to cause the clogged pores that lead to breakouts. Because of these traits most dermatology sources place silicones of this type at the very low end of the comedogenic scale.
Suitable for acne-prone or breakout-prone skin in most cases.
As with any film former, thorough cleansing at the end of the day helps prevent residue buildup that could mix with other occlusive ingredients and raise the risk of congestion over time.
Summary
Polysilicone-35 works as a film former, hair conditioner and skin-softening emollient. Its silicone backbone spreads evenly then sets into a flexible layer that locks in moisture, boosts water resistance and gives products long-wear hold. The attached medium-length alkyl chains add slip and softness which smooth hair cuticles and leave skin with a velvety feel.
While not as famous as dimethicone or cyclomethicone it has carved out a steady niche in sunscreens, styling sprays and long-lasting makeup where durability without heaviness is prized.
Current safety reviews rate it as low risk for irritation, sensitization and pore clogging. Still, everyone’s skin is different so a quick patch test is the safest way to see how your skin reacts before adding any new product to your routine.