Ingredient review

Silicone Quaternium-16 Crosspolymer

INCI: Silicone Quaternium-16/Glycidoxy Dimethicone Crosspolymer

A gentle, positively charged silicone that smooths hair and reduces static without the heavy feel of traditional silicones.

beautyhaircareconditioning agent

In plain English

This is a special type of silicone that carries a positive electrical charge. In hair products, the positive charge helps it stick to the negatively charged surface of damaged or dry hair, forming a thin, flexible film. This film smooths the hair cuticle, reduces frizz, adds shine, and makes hair feel softer and easier to comb. Unlike some older silicones, it is designed to be less likely to build up on hair over time.

Review score

Safety, usefulness, and evidence

4.0Good
4.0/ 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

Silicone Quaternium-16 Crosspolymer 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 Silicone Quaternium-16 Crosspolymer.
  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

A synthetic silicone polymer that has been chemically modified to include quaternary ammonium groups (which give it a positive charge) and crosslinked to form a network structure. This makes it a film-forming, conditioning ingredient that is substantive to hair.

How it works

The positive charge (quaternium) attracts the ingredient to the negatively charged surface of hair, especially damaged areas. Once deposited, the crosslinked silicone network forms a thin, breathable film that smooths the cuticle, reduces friction, and locks in moisture. This film also helps neutralize static electricity, reducing flyaways and frizz.

Pros

Excellent frizz control

The positive charge helps it adhere to damaged hair, forming a smooth film that seals the cuticle and dramatically reduces frizz and flyaways, even in humid conditions.

Low buildup potential

Unlike some non-ionic silicones (like dimethicone), this crosspolymer is designed to be less occlusive and can be more easily removed by gentle cleansers, reducing the risk of heavy buildup over time.

Cons and cautions

May weigh down fine hair

If used in high concentrations or in products not formulated for fine hair, the film-forming nature can make hair feel heavier or less voluminous, especially for those with naturally straight, fine strands.

Not biodegradable

As a synthetic silicone polymer, it is not readily biodegradable in the environment, which is a concern for eco-conscious consumers.

Best for

  • People with dry, damaged, or frizzy hair
  • Those looking for a silicone that is less likely to cause buildup

Use caution if

  • People with very fine, limp hair who prefer lightweight, non-film-forming conditioners
  • Those strictly avoiding all synthetic ingredients

Usage tips

Use a clarifying shampoo once a week if you use multiple silicone-based products to prevent any potential buildup.
For fine hair, look for this ingredient lower on the ingredient list or in rinse-off products rather than leave-in treatments.
Pair with a moisturizing conditioner to balance the film-forming effect with hydration.

Safety summary

Silicone Quaternium-16/Glycidoxy Dimethicone Crosspolymer is considered safe for use in cosmetics at typical concentrations. It has a low irritation and comedogenic risk. The Cosmetic Ingredient Review (CIR) panel has reviewed similar silicone quaternium compounds and found them safe as used.

Research notes

Research on this specific crosspolymer is limited, but studies on similar cationic silicones show they effectively reduce hair surface friction and improve combability. The positive charge enhances deposition on damaged hair, providing conditioning benefits without excessive buildup.

Common label clues

Typical concentration
0.5% to 5%
Regulatory status
Approved for use in cosmetics in the US (FDA), EU, and other major markets. No specific concentration restrictions are in place, but formulators follow good manufacturing practices.
Common uses
Shampoos, Conditioners, Leave-in treatments, Styling products
Environmental note
Silicone quaternium compounds are not readily biodegradable. However, some newer formulations are being developed with improved environmental profiles. Check for brands that prioritize eco-friendly ingredients.

Good to know

  • This ingredient is often used in 'sulfate-free' shampoos and conditioners because it can be rinsed away without harsh detergents.
  • It is considered a 'next-generation' silicone designed to address the buildup issues of older silicones.

Common questions

What is Silicone Quaternium-16 Crosspolymer in beauty products?

This is a special type of silicone that carries a positive electrical charge. In hair products, the positive charge helps it stick to the negatively charged surface of damaged or dry hair, forming a thin, flexible film. This film smooths the hair cuticle, reduces frizz, adds shine, and makes hair feel softer and easier to comb. Unlike some older silicones, it is designed to be less likely to build up on hair over time.

What does Silicone Quaternium-16 Crosspolymer do in a beauty product?

The positive charge (quaternium) attracts the ingredient to the negatively charged surface of hair, especially damaged areas. Once deposited, the crosslinked silicone network forms a thin, breathable film that smooths the cuticle, reduces friction, and locks in moisture. This film also helps neutralize static electricity, reducing flyaways and frizz.

Is Silicone Quaternium-16 Crosspolymer safe for most people?

Silicone Quaternium-16/Glycidoxy Dimethicone Crosspolymer is considered safe for use in cosmetics at typical concentrations. It has a low irritation and comedogenic risk. The Cosmetic Ingredient Review (CIR) panel has reviewed similar silicone quaternium compounds and found them safe as used.

Who should be careful with Silicone Quaternium-16 Crosspolymer?

People with very fine, limp hair who prefer lightweight, non-film-forming conditioners Those strictly avoiding all synthetic ingredients

Research sources

Cosmetic Ingredient Review (CIR) - Safety of Silicone Quaternium CompoundsOpenPubMed - Cationic Silicones for Hair ConditioningOpenPersonal Care Council - Silicone Quaternium-16Open

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.