What Is Bis-Stearyl Ipdi/Peg-795 Copolymer?
Bis-Stearyl IPDI/PEG-795 Copolymer is a lab-made polymer created by linking together isophorone diisocyanate and a long chain of polyethylene glycol, then capping the ends with stearyl alcohol. The stearyl pieces give the molecule a fatty, oil-like character while the PEG backbone attracts water, letting the ingredient bridge the gap between oily and watery phases in a lotion or cream. The finished material looks like a soft wax or viscous liquid and is completely synthetic, so it is not taken from plants or animals.
Chemists first explored this type of copolymer in the late 1990s when brands wanted makeup that stayed on longer yet still felt light. By tweaking the ratio of the building blocks they produced a flexible film former that could survive sweat and movement without cracking. Since then it has shown up in everything from long-wear foundations to waterproof sunscreens.
Production starts with purified isophorone diisocyanate, which is reacted with high-molecular-weight PEG in a controlled environment. Once the backbone reaches the desired length, stearyl alcohol is added to cap any remaining reactive ends. The mixture is then heated, cooled and filtered to remove unreacted material, giving a stable, cosmetic-grade copolymer.
You will most often find Bis-Stearyl IPDI/PEG-795 Copolymer in long-wear or water-resistant makeup, tinted moisturizers, sunscreens, leave-on hair conditioners, styling creams and skin care products that promise a smooth, velvety finish.
Bis-Stearyl Ipdi/Peg-795 Copolymer’s Cosmetic Benefits/Uses
Here is how this ingredient helps a formula perform better on your skin or hair:
- Film forming – Creates a thin, even layer that helps makeup, sunscreen or hair products cling to the surface, boosting wear time and resistance to sweat or rubbing
- Viscosity controlling – Thickens or stabilizes the texture of lotions, creams or gels so they feel silky rather than runny and stay mixed without separating
Who Can Use Bis-Stearyl Ipdi/Peg-795 Copolymer
This copolymer is generally well tolerated by all skin types, including dry and sensitive skin, because it sits on the surface rather than soaking deeply into the epidermis. People with very oily or acne-prone skin may find long-wear formulas that rely on heavy film formers feel a bit occlusive, so lightweight applications are preferable in that case.
The material is fully synthetic and contains no animal-derived components, making it suitable for vegans and vegetarians.
No published data link Bis-Stearyl IPDI/PEG-795 Copolymer to reproductive concerns. Topical use during pregnancy or breastfeeding is considered low risk, but this is not medical advice and anyone who is pregnant or nursing should confirm product choices with a healthcare professional.
The ingredient does not absorb UV light and is not known to increase photosensitivity. It is odorless, has minimal interaction with active ingredients like retinoids or acids, and can be layered under or over most other products without issue.
Potential Side Effects/Adverse Reactions
Individual responses to any cosmetic ingredient can vary. The points below outline potential side effects that have been recorded or are theoretically possible, yet most users will not experience them when the ingredient is properly formulated and used as directed.
- Mild skin irritation or redness, usually due to over-application or pre-existing sensitivity to film formers
- Contact allergy presenting as itching or small rash in people already sensitized to isocyanate-based polymers
- Temporary clogged pores or comedones if applied heavily on very oily skin
- Eye irritation and watering if the raw ingredient or an aerosolized product accidentally contacts the eyes
- Build-up on hair shafts leading to a weighed-down feel or dull appearance when used in leave-in hair products without regular cleansing
If any discomfort or adverse reaction occurs stop using the product and seek advice from a qualified medical professional.
Comedogenic Rating
Rating: 1 out of 5. Despite containing stearyl tails that look fatty on paper, the molecule is so big that it mainly stays on the surface and does not seep into pores. It forms an airy film rather than a greasy plug, so it is unlikely to trigger widespread clogging. People who break out easily can usually use it without trouble, although very heavy layers in long-wear makeup might still feel occlusive on extremely oily skin. There is no published research linking this copolymer to acne flare-ups, and formulators often pair it with volatile silicones or light esters to keep the finish breathable.
Summary
Bis-Stearyl IPDI/PEG-795 Copolymer thickens a formula and lays down a flexible film that helps makeup, sunscreen and hair products stay put through heat sweat and daily movement. It does this by combining a water-loving PEG backbone with oil-loving stearyl ends, letting it bond to both water and oil phases and then dry into a soft mesh on the surface.
The ingredient is a niche pick rather than a mainstream star, popping up mostly in long-wear foundations waterproof mascaras and high-performance sunscreens where durability is a selling point. Its safety profile is solid, with low irritation risk and minimal chance of clogging pores for most users. As with any new cosmetic ingredient it is smart to try a small patch first to make sure your skin plays nicely before committing to full-face or full-body use.