Bis-Stearyl PEG …
INCI: BIS-STEARYL PEG/PPG-8/6 SMDI/PEG-400 COPOLYMER
Reviewed by Daisy · Last updated 2 Jun 2026
A synthetic polymer that controls texture and consistency in skincare formulations
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What Is Bis-Stearyl PEG …?
Bis-Stearyl PEG/PPG-8/6 Smdi/PEG-400 Copolymer is a synthetic polymer—a large molecule made by chemically linking smaller units together. It is designed primarily as a viscosity controlling agent, meaning it adjusts how thick or fluid a product feels and behaves when applied to skin.
This ingredient is used behind the scenes in formulation work rather than for a direct active benefit to skin. Its role is to create the right texture, spreadability and stability in creams, lotions and serums, ensuring products perform as intended when you use them.
How It Works
As a viscosity controlling agent, this polymer works by modifying the flow properties of a formulation. It essentially acts as a thickener or flow modifier, helping to suspend particles evenly throughout the product and giving it body without making it feel heavy or sticky.
The ingredient's structure allows it to interact with other components in the formula, stabilising the overall mixture so that the active ingredients remain properly distributed and the product maintains its intended consistency from first use to the last.
Clinical Evidence & References
Research specifically evaluating this ingredient in skincare is limited. It is classified as a safe ingredient in cosmetic formulations and is approved for use in Europe and other regions; however, direct clinical studies on its effects on skin are not widely published.
Its primary value lies in formulation science rather than clinical efficacy. Any skin benefits you experience from a product containing this ingredient are more likely attributable to other active ingredients in the formula, with this polymer playing a supporting role in product performance.
How to Use
There are no special usage instructions for this ingredient—it works passively within the product. Simply use your skincare product as directed. If a formula feels pleasant to apply and absorbs well, this ingredient has likely contributed to that experience.
Safety & Precautions
Frequently Asked Questions
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