What Is Polysilicone-15?
Polysilicone-15 is a man-made silicone polymer designed to soak up specific wavelengths of ultraviolet light. Chemically it belongs to the siloxane family, a group of molecules built from alternating silicon and oxygen atoms with organic side chains that influence how the ingredient behaves on skin and within a formula.
The material was first explored in the late 1990s when sunscreen researchers looked for photo-stable filters that would not break down easily under sunlight. Traditional organic UV filters often degraded after lengthy exposure, so chemists turned to silicone chemistry for a sturdier backbone. By grafting UV-absorbing groups onto a flexible siloxane chain they created Polysilicone-15, launching it into European sun care products in the early 2000s. Regulatory approval followed in many regions, leading to wider use in mainstream cosmetics.
Manufacturing starts with a base of cyclic siloxanes that are opened and linked together in a controlled polymerisation step. UV-absorbing benzylidene malonate groups are attached along the chain, then the finished polymer is purified and blended into a liquid or gel carrier for easy dispersion in cosmetic bases.
You will most often spot Polysilicone-15 in sunscreens, day creams with SPF, tinted moisturisers, setting sprays, hair products that claim UV protection, colour-protecting shampoos and leave-in conditioners, as well as certain anti-aging serums where formulators want to shield skin from photo-damage without a heavy feel.
Polysilicone-15’s Cosmetic Benefits/Uses
Formulators reach for Polysilicone-15 because it delivers multiple protective roles in one ingredient.
- Light Stabilizer – helps keep other light-sensitive ingredients such as vitamins or plant extracts from breaking down when the product is exposed to daylight
- UV Absorber – soaks up UVB rays, converting them into less damaging heat that dissipates off the skin surface, which helps prevent sunburn and slows the formation of free radicals
- UV Filter – boosts overall SPF performance, allowing lighter textures and clearer finishes compared to some traditional filters, while also extending colour durability in hair and makeup products
Who Can Use Polysilicone-15
Because it is a lightweight non-greasy silicone polymer, Polysilicone-15 suits most skin types including oily, combination, normal and dry. Sensitive skin generally tolerates it well since the molecule is large and stays on the surface rather than penetrating deeply. Those with very reactive or allergy-prone skin should still keep an eye on how their skin feels, as with any new cosmetic ingredient.
The material is fully synthetic and contains no animal-derived raw materials, so products that list it as the only potential animal concern are usually acceptable for vegans and vegetarians. As always check the complete ingredient list for beeswax, lanolin or similar additives that might appear alongside it.
Current safety assessments show minimal systemic absorption, which makes Polysilicone-15 unlikely to pose a risk for pregnant or breastfeeding women when used in topical products. This is not medical advice and anyone who is pregnant or nursing should run all skincare choices past a qualified healthcare provider to be on the safe side.
The ingredient does not make skin more sensitive to sunlight. In fact it helps absorb UVB rays, so it is commonly used to lower the chance of sunburn. It is also fragrance-free and dye-free, two factors that further reduce the odds of reactivity for many users.
Potential Side Effects/Adverse Reactions
Reactions to topical Polysilicone-15 differ from person to person. The following is a list of potential side effects that could occur, though they are uncommon when the ingredient is included at approved levels in well-formulated products.
- Mild skin redness or itching
- Stinging sensation if applied to broken or freshly exfoliated skin
- Allergic contact dermatitis in individuals sensitised to silicone polymers
- Temporary eye irritation if the product migrates into the eyes
- Build-up on hair shafts leading to a weighed-down feel in some leave-in formulas
If you notice any of the reactions listed above stop using the product and seek advice from a healthcare professional or dermatologist.
Comedogenic Rating
Rating: 1 / 5
Polysilicone-15 is a large, non-oily silicone polymer that mostly sits on the surface of skin rather than seeping into pores. Its film-forming nature helps it glide without leaving a greasy residue, so it is unlikely to clog follicles. Because it is used at low concentrations and has no fatty acids or waxes that typically trigger congestion, the risk of breakouts is minimal.
Suitable for acne-prone or easily congested skin
Some people notice a heavy feel when several silicone-based products are layered. If you already use many silicones, pay attention to how your skin responds and cleanse thoroughly at the end of the day to avoid build-up.
Summary
Polysilicone-15 acts as a light stabiliser, UV absorber and UV filter. Its siloxane backbone keeps it stable under sunlight while the attached benzylidene malonate groups soak up UVB rays and convert them to harmless heat. This dual nature lets it protect both the formula and the skin in a single step.
Although not as famous as filters like avobenzone or octinoxate, it has carved out a steady niche in European sun care lines, spray sunscreens and colour-protecting hair products thanks to its transparency and lightweight feel.
Current data shows it is safe for topical use with very low irritation or absorption potential. As with any new cosmetic ingredient it is smart to patch test a product that contains Polysilicone-15 to ensure your skin agrees with it.