Ingredient review

Quaternium-93

INCI: Quaternium-93

Quaternium-93 is a synthetic conditioning ingredient that helps reduce frizz and static in hair, but it may not suit those with very sensitive scalps.

beautyskincarehaircare

In plain English

Quaternium-93 is a man-made ingredient that coats the hair shaft to make it feel smoother and less flyaway. It works by neutralizing static electricity and adding a thin, positively charged layer that helps hair lie flat. In skincare, it can also provide a silky after-feel, though it is far more common in hair products.

Review score

Safety, usefulness, and evidence

3.5Good
3.5/ 5

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
How reviews are scored

Quick decision guide

Useful, but context matters

Quaternium-93 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.

  1. Step 1Start with the score, then check the irritation and clogging risk before judging Quaternium-93.
  2. Step 2Use the "Best for" and "Use caution if" sections to match the ingredient to your skin, not just to a marketing claim.
  3. 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

low

Less likely to sting, burn, or bother most users, though sensitive skin can still react.

Clogging risk

low

Less likely to feel heavy or contribute to clogged pores for most skin types.

Evidence level

moderate

There is useful support, but formula details and claim strength still matter.

What it is

Quaternium-93 is a quaternary ammonium compound, a type of positively charged molecule that binds to negatively charged hair or skin surfaces. It is synthetically produced and belongs to a family of ingredients known for their conditioning and antistatic properties.

How it works

In a cosmetic product, Quaternium-93 deposits a thin film on the hair or skin. Its positive charge attracts it to the negatively charged surface of damaged hair or skin, reducing static electricity and improving manageability. This film also helps lock in moisture and provides a temporary smoothing effect.

Pros

Effective antistatic

Quaternium-93 quickly neutralizes static electricity, making hair less flyaway and easier to style, especially in dry or cold weather.

Lightweight feel

Unlike heavier conditioning oils, Quaternium-93 provides a smooth feel without weighing down fine or thin hair.

Cons and cautions

Potential buildup

With frequent use, especially in leave-in products, Quaternium-93 can accumulate on hair, leading to dullness or a coated feel over time.

Synthetic origin

As a synthetic quaternary compound, it may not appeal to those seeking natural or biodegradable alternatives, and its production has a higher environmental footprint.

Best for

  • People with frizzy or static-prone hair
  • Those looking for a lightweight conditioner for fine hair

Use caution if

  • Individuals with very sensitive or easily irritated scalps
  • Those who prefer entirely natural or plant-based ingredients

Usage tips

Use a clarifying shampoo once a week if you notice buildup from conditioning ingredients like Quaternium-93.
Start with a product that lists it lower on the ingredient label to minimize potential irritation on sensitive scalps.
Pair with a moisturizing leave-in conditioner if your hair feels dry after using a Quaternium-93-heavy product.

Safety summary

Quaternium-93 is considered safe for use in rinse-off and leave-on products at typical concentrations. It has low irritation and comedogenic potential, but individuals with very sensitive skin or scalps should patch test first. Long-term safety data is limited but no major concerns have been raised by regulatory panels.

Research notes

Research on Quaternium-93 is limited compared to more common quats. Most safety data comes from industry assessments and analog studies of similar quaternary compounds. The Cosmetic Ingredient Review (CIR) has evaluated related ingredients and found them safe within recommended limits.

Common label clues

Typical concentration
0.1% to 2%
Regulatory status
Approved for use in cosmetics in the EU, US, and many other regions, subject to concentration limits and safety assessments by bodies like the Cosmetic Ingredient Review (CIR).
Common uses
Conditioners, Shampoos, Leave-in treatments, Styling products
Environmental note
As a synthetic quaternary ammonium compound, Quaternium-93 may not be readily biodegradable. Look for products with eco-friendly certifications if environmental impact is a concern.

Good to know

  • Quaternium-93 is often used in combination with other conditioning agents to balance performance.
  • It is not the same as Quaternium-15, which is a formaldehyde-releasing preservative.

Common questions

What is Quaternium-93 in beauty products?

Quaternium-93 is a man-made ingredient that coats the hair shaft to make it feel smoother and less flyaway. It works by neutralizing static electricity and adding a thin, positively charged layer that helps hair lie flat. In skincare, it can also provide a silky after-feel, though it is far more common in hair products.

What does Quaternium-93 do in a beauty product?

In a cosmetic product, Quaternium-93 deposits a thin film on the hair or skin. Its positive charge attracts it to the negatively charged surface of damaged hair or skin, reducing static electricity and improving manageability. This film also helps lock in moisture and provides a temporary smoothing effect.

Is Quaternium-93 safe for most people?

Quaternium-93 is considered safe for use in rinse-off and leave-on products at typical concentrations. It has low irritation and comedogenic potential, but individuals with very sensitive skin or scalps should patch test first. Long-term safety data is limited but no major concerns have been raised by regulatory panels.

Who should be careful with Quaternium-93?

Individuals with very sensitive or easily irritated scalps Those who prefer entirely natural or plant-based ingredients

Research sources

Cosmetic Ingredient Review (CIR) - Safety Assessment of Quaternary Ammonium CompoundsOpenEuropean Chemicals Agency (ECHA) - Quaternium-93 InformationOpenPubMed - Quaternary Ammonium Compounds in CosmeticsOpen

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.