TRIMETHYLSILOXYSILICATE

📋 Quick facts

Description: TRIMETHYLSILOXYSILICATE — silicone, film-forming, adds water resistance.

All Functions: silicone, film-forming, adds water resistance

Quick Facts:

• Category: emollient

Proven Benefits At A Glance:

• A silicone-based ingredient used in cosmetics as a film-former, thickener, and skin conditioner
• Functions as both a soft and hard film-forming agent in sunscreens and skincare products
• Creates a persistent, non-occlusive layer on skin that resists washing
• Deemed safe by the Cosmetic Ingredient Review Expert Panel when formulated to avoid respiratory irritation
• Can enhance UV protection in sunscreens when combined with other film-forming agents

⚗️ Chemical Overview

See also: Polymethylsilsesquioxane/trimethylsiloxysilicate (monomer of); Trimethylsiloxysilicate (annotation moved to).

Source(s): PubChem, via PubChem

📊 Comedogenicity

🛡️ Safety rating

Safety tier is a starting heuristic from regulatory status and comedogenic rating, not a dermatological verdict — see our Terms for the full disclaimer. Research confidence reflects how many real cited studies back this ingredient, not the strength of their findings.

🌍 Regulatory Status

💧 Skin Type Compatibility

⚠️ Don’t Combine With

📚 Research & Evidence

🔬 The Science

Trimethylsiloxysilicate (often abbreviated TMSS) is a modified silicone polymer that belongs to a family of ingredients called siloxysilicates. Here’s what the research shows about how it works and what it does. **What it does in formulas:** The Cosmetic Ingredient Review Expert Panel identified multiple functions for trimethylsiloxysilicate in cosmetics (Int J Toxicol, 2013). #1: It acts as an antifoaming agent, preventing unwanted bubbles. #2: It works as an anticaking agent and bulking agent, helping powders flow smoothly. #3: It conditions skin as an emollient (softening) and occlusive (moisture-barrier) agent. #4: It modifies slip—the glide and feel of a product on skin.

#5: It increases viscosity in non-aqueous (oil-based) formulations, making products thicker. **Film-forming and durability:** One of trimethylsiloxysilicate’s most notable properties is its ability to form a durable film on skin. In a 2021 study on essential oil delivery (Int J Pharm, 2021), researchers used a 100% trimethylsiloxysilicate resin specifically because it creates “a very substantive and non-occlusive film”—meaning it sticks around on skin without blocking it from breathing. A 1988 analysis (Int J Cosmet Sci, 1988) found that when combined with other silicones, trimethylsiloxysilicate improves “substantivity,” the ability of a product to stay on skin through multiple wash cycles. The resin’s low solubility is what drives this persistence.

**Use in sunscreens:** Recent research (Polymers (Basel), 2024) explored trimethylsiloxysilicate as a “hard film” component in multi-layer sunscreen formulations. When combined with other film-forming agents and powder ingredients with similar chemical structures, it enhanced UV protection measurably: sun protection factor (SPF) increased by 61.58% and UVA protection factor (PFA) increased by 43.84% in the tested formula. The ingredient’s interaction with other components helped prevent clumping and created a more uniform protective layer. **Safety:** The Cosmetic Ingredient Review Expert Panel (Int J Toxicol, 2013) concluded that trimethylsiloxysilicate is safe as used in cosmetics, provided the final product is formulated to avoid irritating or sensitizing the respiratory tract—a consideration for powder formulations or spray products.

**Limitations in available research:** The sources provided focus mainly on technical functionality and safety assessment. There is limited consumer-facing clinical data on specific skin benefits like anti-aging, acne treatment, or visible texture improvement. Most studies examine trimethylsiloxysilicate within complex multi-ingredient formulations, making it difficult to isolate its individual contribution to skin appearance or feel.

📄 Related Research

Matched by search — not necessarily verified support for every statement above.

• Becker LC et al. (2013). Safety assessment of silylates and surface-modified siloxysilicates. Int J Toxicol.
• Chen Y et al. (2024). Structural Similarity-Induced Inter-Component Interaction in Silicone Polymer-Based Composite Sunscreen Film for Enhanced UV Protection. Polymers (Basel).
• Sounouvou HT et al. (2021). Development of a highly persistent silicone-based sprayable emulsion containing essential oils for treatment of skin infections. Int J Pharm.
• Disapio A et al. (1988). Silicones: use of substantive properties on skin and hair. Int J Cosmet Sci.
• Ogihara H et al. (2011). One-step electrophoretic deposition for the preparation of superhydrophobic silica particle/trimethylsiloxysilicate composite coatings. J Colloid Interface Sci.

🧴 Products Containing TRIMETHYLSILOXYSILICATE

• Vogue Vogue Colorissimo
• Funk Crema para peinar
• Dermato Science SensilianeSun lait protecteur 50+
• Kiko Tuscan sunshine eyeliner duo 02
• Deborah 24 Ore Long Lasting – Crayon Lèvres Longue Tenue
• L’OREAL NORGE AS L’Oreal Blush True Match Rose Bonne Mine 165
• Estēe Lauder Double Wear
• Les Cosmetiques Facial pieles sensibles spf30 sun ultimate
• Les Cosmetiques Loción solar spf30 sun ultimate
• Les Cosmetiques Loción solar spf30 sun ultimate
• L’OREAL NORGE AS L’Oréal Paris True Match 145 Bois de Rose Blush
• Deliplus Pintalabios Color Fix 01
• MAC Studio Radiance 24HR Luminous Lift Concealer NC11
• Kiko Tuscan sunshine eyeliner duo 03
• Red One Conditioning Beard & Mustache Keratin Care Oil Hipster Style
• L’OREAL NORGE AS L’Oreal Infallible Foundation Porcelaine 015
• L’OREAL NORGE AS L’Oreal Foundation Infallible Lin/Linen 100
• Ertia
• Revlon Dramatic Definition 251 Noir Intense
• Nautical Nonsense Palette
• bareMinerals Performance Wear Liquid Foundation
• revlon colorstay full coverage
• Revlon Colorstay™ Foundation 110 Ivory
• Blue Lizard Sensitive Mineral Sunscreen
• Bobbi Brown Long-wear cream shadow stick
• Shiseido Future Solution LX Sérum Intensif Contours Fermeté Shiseido
• Shiseido Lait Bronzant SPF 6
• Shiseido Expert Anti-Age Solaire Crème Protectrice SPF 30
• Nyx NYX Professional Makeup Lingerie XXL 05 Stripd Down Lippenstift
• Aveda AVEDA Sun Care Protective Hair Veil
• Avon Skin so Soft
• EYEKO EYEKO SPORT WATERPROOF
• Ole Henriksen,OleHenriksen Banana Bright Vitamin C Serum
• Revlon Delineador retráctil Colorstay
• Cien Fond de teint foundation 020 natural beige
• Bourjois, Bourjois Paris Vernis à ongles 1 seconde n°12 Rouge Obscur
• A-DERMA, Pierre Fabre A-Derma Crème mains au Lait d’Avoine Rhealba
• Corinne de farme Spray protecteur sensitive +
• Corine de Farme Lait hydratant protège & bronze spf 30
• L’Oréal, L’Oreal Consumer products, L’Oréal Paris Nude Magique BB Powder (Peau claire)