What Is Polyester-27?
Polyester-27 is a synthetic copolymer created by linking together glycerin, hydroxystearic acid, dilinoleic acid and hydroxypropyldimethicone, then finishing or “end-capping” the chain with octyldodecanol. The result is a lightweight flexible film former with both water-loving and oil-loving sections that help it spread easily across skin or hair. Developers began exploring this type of hybrid polyester in the early 2000s when cosmetic chemists were searching for silicone-compatible polymers that could improve wear time without a heavy feel. Commercial production usually starts with plant-derived glycerin and fatty acids that are reacted under controlled heat and vacuum, followed by incorporation of the silicone-containing segment and final capping to fine-tune texture and stability.
Because of its ability to create an invisible breathable film, Polyester-27 shows up most often in long-wear makeup such as foundations, tinted moisturizers and liquid lipsticks. It is also common in sunscreen lotions, smoothing hair serums, sheet-mask essences and certain anti-aging primers where staying power and a soft finish are key selling points.
Polyester-27’s Cosmetic Benefits/Uses
In formulations Polyester-27 delivers one core benefit thanks to its primary function.
Film forming: When applied to skin or hair the polymer dries to a thin flexible layer that locks pigments in place, boosts water resistance, reduces transfer and helps active ingredients stay on the surface longer. This film also gives products a silky slip during application and can blur minor lines or uneven texture for a smoother appearance.
Who Can Use Polyester-27
Polyester-27 is considered friendly for most skin types. Its lightweight film feels comfortable on normal, combination and oily skin, while the soft‐focus finish can help dry or mature skin look smoother without adding heaviness. Those with very sensitive or highly reactive skin should proceed cautiously since any synthetic polymer has a small chance of triggering irritation.
The raw materials used to make Polyester-27 are typically sourced from plants and synthetic silicones, not animals, so products containing it are generally suitable for vegans and vegetarians. As always, anyone following a strict lifestyle should verify the full formula and manufacturing practices with the brand.
The ingredient is not known to be absorbed into the bloodstream or to interfere with hormonal pathways, so it is regarded as safe for use during pregnancy or breastfeeding. This is not medical advice and pregnant or nursing individuals should discuss all skincare products with their physician to be sure they align with personal health needs.
Polyester-27 does not make skin more sensitive to sunlight and can actually support the durability of sunscreens by helping them stay in place. No special daytime precautions are required beyond regular sun protection habits.
Potential Side Effects/Adverse Reactions
Responses to any cosmetic ingredient vary from person to person. The effects listed below are potential outcomes and most users will not experience them when the product is well formulated and used as directed.
- Mild skin irritation – a small percentage of users may notice redness stinging or itching, especially if they have preexisting sensitivity
- Contact dermatitis – very rare cases of allergic reaction with rash or swelling can occur if an individual becomes sensitized to the polymer
- Clogged pores or breakouts – in acne‐prone skin the breathable film could still trap oil and debris leading to comedones or pimples
- Eye discomfort – if product containing Polyester-27 migrates into the eye it can cause watering or temporary burning
If any of these reactions develop discontinue use immediately and consult a healthcare professional for guidance.
Comedogenic Rating
Rating: 1/5 (low)
Polyester-27 forms a breathable surface film that stays mostly on top of the skin instead of sinking into pores. Its large molecular weight and balanced oil–water profile limit its ability to feed acne bacteria or block follicles so it is considered low clogging. In richer formulas or when layered with heavy occlusives it could still trap sebum and debris which might trigger bumps in very reactive skin.
Most acne-prone users tolerate Polyester-27 well when it is part of a lightweight makeup or sunscreen.
No standardized comedogenicity studies have been published for this polymer so the rating draws on its chemistry and consumer feedback. Formulation context and individual skin type ultimately determine how pore-friendly it will be.
Summary
Polyester-27 is prized for one main job: forming a thin flexible film that anchors pigments and actives boosts water resistance cuts transfer and leaves a smooth soft-focus finish. Its mix of glycerin fatty acids and silicone segments lets it glide easily yet set into a durable layer.
While not a household name it shows up regularly in long-wear makeup sunscreens primers and hair serums for brands aiming at performance without heaviness.
Overall safety is high with a low likelihood of irritation or systemic absorption. Even so skin can react unpredictably so it is smart to patch test any new product containing Polyester-27 before full use.