What Is Diisostearoyl Trimethylolpropane Siloxy Silicate?
Diisostearoyl Trimethylolpropane Siloxy Silicate is a hybrid molecule that marries fatty acid esters with a silicone-based backbone. The fatty part comes from isostearic acid, which is sourced from natural vegetable oils, while the silicate segment is derived from silica, the main component of sand. Chemists link these two parts together to create a lightweight yet durable material that behaves like a film-forming resin when applied to skin. The ingredient first appeared in color cosmetics in the early 2000s as brands searched for alternatives to heavier waxes that could still deliver long-lasting wear. Production involves esterifying isostearic acid with trimethylolpropane to form diisostearoyl trimethylolpropane, then reacting that with siloxy silicate through a controlled condensation process. The finished ingredient shows up most often in long-wear foundations, lipsticks, tinted moisturizers, sunscreens, waterproof mascaras and some high performance primers where it helps products stay put without feeling greasy.
Diisostearoyl Trimethylolpropane Siloxy Silicate’s Cosmetic Benefits/Uses
This ingredient is mainly valued for one key role in personal care formulas.
Skin conditioning: It forms a flexible breathable film that smooths the skin surface, boosts spreadability and locks in moisture. The result is makeup that glides on evenly, resists smudging and leaves the complexion feeling soft instead of tight or dry.
Who Can Use Diisostearoyl Trimethylolpropane Siloxy Silicate
Because it is lightweight and non greasy, this film former suits most skin types including dry, normal, combination and oily skin. Sensitive skin usually tolerates it as well since the molecule stays on the surface rather than sinking deep into the skin, lowering the chance of stinging or redness. Those with very acne prone skin should note that any occlusive film can sometimes trap oil and bacteria, so watch for breakouts when first trying a product that contains it.
The ingredient is made from vegetable derived isostearic acid and silica, with no animal sourced material or animal testing tied to its production, making it suitable for both vegans and vegetarians.
Current research shows no special risks for women who are pregnant or breastfeeding when this ingredient is used in a topical cosmetic formula. Still, this is not medical advice and anyone who is pregnant or nursing should show the full product label to a doctor before use to be extra safe.
Diisostearoyl Trimethylolpropane Siloxy Silicate does not make skin more sensitive to sunlight so it is not considered a photosensitizer. It also plays well with common actives like vitamin C, retinoids and acids because it is largely inert and sits on top of the skin.
Potential Side Effects/Adverse Reactions
Side effects from topical use can vary from person to person. The points below describe potential issues, though most users will not notice any problems when the ingredient is used as intended by the product maker.
- Mild skin irritation such as redness or itching
- Clogged pores or breakouts in very acne prone skin
- Allergic contact rash in people sensitive to esters or silicones
- Eye irritation if the product migrates into the eyes
- Dry or tight feeling if layered with many other film formers
If you experience any of the above stop using the product and seek advice from a healthcare professional.
Comedogenic Rating
Rating: 2/5
Most silicones score between 0 and 1 but the ingredient’s diisostearoyl fatty chains add a touch of richness that can sit in pores, nudging the score up to a 2. This means it has a low to moderate chance of clogging pores, especially if layered over heavy creams or in humid climates. It should be fine for many acne-prone users yet could contribute to breakouts if the overall routine is already quite occlusive or if you are highly susceptible to comedogenic build-up.
Those dealing with stubborn blackheads or cystic acne may want to limit leave-on products that pair this resin with lots of other fatty esters and waxes, as the combined load can tip the skin toward congestion.
Summary
Diisostearoyl Trimethylolpropane Siloxy Silicate is a lightweight film former that conditions skin, improves spreadability and locks makeup in place so color stays vibrant through heat, sweat and daily wear. It achieves these perks by creating a breathable lattice on the surface that flexes with facial movement while sealing in moisture.
The ingredient enjoys steady use in long-wear foundations, liquid lipsticks and waterproof mascaras but it is not a blockbuster found in every formula. Brands focused on transfer resistance and clean feel tend to feature it most often.
Current data shows it is safe for topical use with very low irritation or allergy rates. Still, every skin is different so run a small patch test first whenever you try a new product containing this resin, especially if you are prone to sensitivity or breakouts.