Ingredient review
Polyquaternium-73
INCI: Polyquaternium-73
A gentle synthetic polymer that smooths hair and skin by forming a light, non-sticky film, with low irritation potential.
In plain English
Polyquaternium-73 is a man-made ingredient that coats the surface of hair strands or skin to reduce frizz, static electricity, and roughness. Think of it like a very thin, invisible glove that makes hair feel silkier and skin feel softer without leaving a greasy residue. It's commonly found in shampoos, conditioners, and body washes.
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-73 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-73.
- 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-73 is a cationic (positively charged) polymer belonging to the polyquaternium family. It is synthesized from acrylic acid and other monomers to create a water-soluble, film-forming compound that binds to negatively charged surfaces like hair and skin.
How it works
In a cosmetic product, Polyquaternium-73 carries a positive charge that attracts it to the negatively charged surface of hair or skin. Once applied, it forms a thin, flexible film that smooths the cuticle, reduces static electricity, and improves the sensory feel. In rinse-off products, a small amount remains on the hair or skin after rinsing, providing lasting conditioning benefits.
Pros
Lightweight conditioning
Provides a silky feel without weighing hair down, making it suitable for fine or oily hair types.
Low irritation potential
Generally well-tolerated on skin and scalp, with a low risk of irritation or clogging pores.
Cons and cautions
Possible buildup over time
With repeated use, especially in leave-on products, the polymer can accumulate on hair, leading to dullness or stiffness if not clarified periodically.
Synthetic origin
As a man-made polymer, it may not appeal to those seeking fully natural or biodegradable ingredients.
Best for
- People with frizzy or static-prone hair
- Those looking for a lightweight conditioner without heavy oils
Use caution if
- Individuals with very fine or low-porosity hair who experience buildup easily
Usage tips
Safety summary
Polyquaternium-73 is considered safe for use in cosmetics at typical concentrations. It has low skin and eye irritation potential and is not known to be sensitizing. No significant safety concerns have been raised by regulatory bodies.
Research notes
Research on polyquaterniums generally supports their safety and efficacy as conditioning agents. Specific studies on Polyquaternium-73 are limited, but the broader class is well-documented. The Cosmetic Ingredient Review (CIR) panel has reviewed similar polyquaterniums and found them safe as used.
Common label clues
- Typical concentration
- 0.1% to 2% in rinse-off products; lower in leave-on formulas
- Regulatory status
- Approved for use in cosmetics in the US (FDA) and EU (CosIng) with no known restrictions at typical concentrations.
- Common uses
- Shampoos, Conditioners, Leave-in treatments, Styling products, Body washes
- Environmental note
- As a synthetic polymer, its biodegradability varies by formulation. Some polyquaterniums are not readily biodegradable, so environmental impact depends on wastewater treatment and product disposal.
Good to know
- Polyquaternium-73 is often used in combination with other conditioning agents for a multi-benefit effect.
- It is compatible with both anionic and nonionic surfactants, making it versatile in formulations.
Common questions
What is Polyquaternium-73 in beauty products?
Polyquaternium-73 is a man-made ingredient that coats the surface of hair strands or skin to reduce frizz, static electricity, and roughness. Think of it like a very thin, invisible glove that makes hair feel silkier and skin feel softer without leaving a greasy residue. It's commonly found in shampoos, conditioners, and body washes.
What does Polyquaternium-73 do in a beauty product?
In a cosmetic product, Polyquaternium-73 carries a positive charge that attracts it to the negatively charged surface of hair or skin. Once applied, it forms a thin, flexible film that smooths the cuticle, reduces static electricity, and improves the sensory feel. In rinse-off products, a small amount remains on the hair or skin after rinsing, providing lasting conditioning benefits.
Is Polyquaternium-73 safe for most people?
Polyquaternium-73 is considered safe for use in cosmetics at typical concentrations. It has low skin and eye irritation potential and is not known to be sensitizing. No significant safety concerns have been raised by regulatory bodies.
Who should be careful with Polyquaternium-73?
Individuals with very fine or 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.