Ingredient review
Polyquaternium-27
INCI: Polyquaternium-27
A gentle synthetic polymer that smooths hair and reduces flyaways without heavy buildup.
In plain English
Polyquaternium-27 is a man-made polymer (a long chain of repeating units) that carries a positive charge. In hair products, this positive charge helps it stick to the negatively charged surface of hair strands, forming a thin, flexible film. This film smooths the hair cuticle, reduces static electricity, and makes hair feel softer and easier to comb. It is also used in some skincare products to create a silky, non-greasy feel on the skin.
Review score
Safety, usefulness, and evidence
Potentially useful with some tradeoffs
The evidence base is useful, but some claims depend heavily on the formula.
Risk flags are low for most users, though the finished product can still irritate.
- Source
- synthetic
- Evidence
- moderate
- Irritation
- low
- Clogging risk
- low
Quick decision guide
Useful, but context matters
Polyquaternium-27 is generally a lower-concern ingredient when the full formula suits your skin.
Plain-English read
Treat this as a practical screening step before you compare products that contain this ingredient.
- Step 1Start with the score, then check the irritation and clogging risk before judging Polyquaternium-27.
- Step 2Use the "Best for" and "Use caution if" sections to match the ingredient to your skin, not just to a marketing claim.
- Step 3If a product stings, breaks you out, or worsens irritation, judge the finished formula and stop using it even if the ingredient scores well.
Score terms in plain English
Irritation risk
lowLess likely to sting, burn, or bother most users, though sensitive skin can still react.
Clogging risk
lowLess likely to feel heavy or contribute to clogged pores for most skin types.
Evidence level
moderateThere is useful support, but formula details and claim strength still matter.
What it is
Polyquaternium-27 is a synthetic cationic polymer belonging to the polyquaternium family. It is produced by reacting a quaternary ammonium compound with a polymer backbone, giving it a permanent positive charge.
How it works
When applied to hair or skin, the positive charge on Polyquaternium-27 is attracted to the negatively charged surfaces of hair and skin. It forms a thin, even film that coats the surface, reducing friction and static. This film also helps other ingredients adhere better and provides a smooth, silky feel.
Pros
Excellent static control
Polyquaternium-27 effectively neutralizes static electricity, reducing flyaways and making hair more manageable in dry or humid conditions.
Lightweight conditioning
Unlike some heavier oils or silicones, this polymer provides a smooth feel without weighing down fine or thin hair.
Cons and cautions
Potential buildup over time
Because it forms a film on the hair, repeated use without clarifying can lead to a dull or coated appearance, especially on low-porosity hair.
Not fully biodegradable
As a synthetic polymer, Polyquaternium-27 may persist in the environment longer than natural alternatives, though it is generally considered safe for aquatic life at low concentrations.
Best for
- People with frizzy or static-prone hair
- Those looking for a lightweight conditioner for fine hair
Use caution if
- Individuals with very low-porosity hair who experience buildup easily
Usage tips
Safety summary
Polyquaternium-27 is considered safe for use in cosmetics at typical concentrations. It has low irritation and sensitization potential. The Cosmetic Ingredient Review (CIR) panel has reviewed similar polyquaterniums and found them safe as used.
Research notes
Research on Polyquaternium-27 specifically is limited, but the broader polyquaternium family has been studied for safety and efficacy. Studies show these polymers are effective conditioners with low toxicity. The CIR has reviewed several polyquaterniums and concluded they are safe in current use practices.
Common label clues
- Typical concentration
- 0.1% to 2%
- Regulatory status
- Approved for use in cosmetics in the EU, US, and many other regions. No known restrictions at typical use levels.
- Common uses
- Conditioners, Leave-in treatments, Styling products, Shampoos
- Environmental note
- Polyquaternium-27 is not readily biodegradable, but it is not classified as bioaccumulative. Its environmental impact is considered low at the concentrations used in rinse-off products.
Good to know
- Polyquaternium-27 is often found in 'smoothing' or 'anti-frizz' products.
- It is compatible with most anionic surfactants, making it easy to formulate into shampoos.
Common questions
What is Polyquaternium-27 in beauty products?
Polyquaternium-27 is a man-made polymer (a long chain of repeating units) that carries a positive charge. In hair products, this positive charge helps it stick to the negatively charged surface of hair strands, forming a thin, flexible film. This film smooths the hair cuticle, reduces static electricity, and makes hair feel softer and easier to comb. It is also used in some skincare products to create a silky, non-greasy feel on the skin.
What does Polyquaternium-27 do in a beauty product?
When applied to hair or skin, the positive charge on Polyquaternium-27 is attracted to the negatively charged surfaces of hair and skin. It forms a thin, even film that coats the surface, reducing friction and static. This film also helps other ingredients adhere better and provides a smooth, silky feel.
Is Polyquaternium-27 safe for most people?
Polyquaternium-27 is considered safe for use in cosmetics at typical concentrations. It has low irritation and sensitization potential. The Cosmetic Ingredient Review (CIR) panel has reviewed similar polyquaterniums and found them safe as used.
Who should be careful with Polyquaternium-27?
Individuals with very low-porosity hair who experience buildup easily
Research sources
Ingredient reviews are educational and are not medical advice. Patch test new products and ask a licensed clinician about persistent irritation, allergies, pregnancy-specific questions, or diagnosed skin conditions.