Polyester-7
INCI: POLYESTER-7
Reviewed by Kate · Last updated 14 Aug 2026
A synthetic polymer that creates a protective layer whilst supporting product texture
Best For Skin Types
All, Dry, Mature, Sensitive
Addresses
Usage Frequency
Daily
What Is Polyester-7?
Polyester-7 is a synthetic polymer—a large molecule made up of repeating units of polyester chains. It is created through chemical synthesis rather than derived from natural sources. In skincare formulations, it functions primarily as a film-forming agent, meaning it creates a thin, breathable layer across the skin surface.
Beyond film formation, Polyester-7 also acts as a skin conditioning agent and helps to control the viscosity (thickness) of formulations, making products easier to apply and improving their sensory feel. It is used sparingly in skincare products, appearing in roughly 0.1% of formulations.
How It Works
Polyester-7 works by depositing a thin, flexible polymer film on the skin surface when a product is applied and allowed to dry. This film acts as an occlusive layer, reducing the amount of water that evaporates from the skin—a mechanism known as occlusion. Because the film is breathable, it does not suffocate the skin or trap bacteria.
Within the formula itself, Polyester-7 increases viscosity, which means it thickens the product and gives it body. This makes formulations easier to dispense and apply evenly, and can improve the overall sensory experience of using a skincare product.
Clinical Evidence & References
The research base specifically addressing Polyester-7 in skincare is limited. However, the broader principle of film-forming polymers creating occlusive barriers is well established in dermatology. Occlusive ingredients have been shown to help support the skin barrier and reduce transepidermal water loss, which is particularly relevant for ageing and compromised skin.
Evidence suggests that maintaining skin hydration and barrier function is important for optimal skin health and appearance, and for supporting the skin's natural immune and repair mechanisms. Polyester-7 may contribute to these outcomes through its film-forming action, though long-term clinical studies specific to this ingredient would strengthen current understanding.
How to Use
Polyester-7 is typically used in formulations at very low concentrations and does not require special application guidance. It will be listed in the ingredients list of any product that contains it. Allow products containing this ingredient time to dry or set fully on the skin to allow the polymer film to form properly, which will optimise its conditioning and protective benefits.
Safety & Precautions
Frequently Asked Questions
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