Ingredient review

Methylene Bis-Benzotriazolyl Tetramethylbutylphenol (Nano) Copolymer

INCI: METHYL ACRYLATE/METHYLENE DROMETRIZOLE METHACRYLATE COPOLYMER

A highly effective, photostable broad-spectrum UV filter that is gentle on skin and leaves minimal white cast.

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In plain English

This ingredient is a sunscreen agent that works like a tiny shield on your skin. It both absorbs harmful UV rays and scatters them like a mirror, giving you broad protection against UVA and UVB. Because it's made of very small particles, it spreads evenly and doesn't leave a heavy white layer like some older sunscreens.

Review score

Safety, usefulness, and evidence

4.5Excellent
4.5/ 5

Strong fit for many routines

The evidence base is relatively strong for its common cosmetic role.

Risk flags are low for most users, though the finished product can still irritate.

Source
synthetic
Evidence
strong
Irritation
low
Clogging risk
low
How reviews are scored

Quick decision guide

Easy yes for most routines

Methylene Bis-Benzotriazolyl Tetramethylbutylphenol (Nano) Copolymer 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 Methylene Bis-Benzotriazolyl Tetramethylbutylphenol (Nano) Copolymer.
  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

strong

There is a stronger practical or research basis for the ingredient role described here.

What it is

A synthetic copolymer that combines an organic UV-absorbing molecule (drometrizole) with a polymer backbone, creating a particle that both absorbs and reflects UV light. It is often used in nanoparticle form for better cosmetic elegance.

How it works

When applied to skin, the particles form a thin, even film. The organic part absorbs UV energy and converts it into harmless heat, while the polymer structure scatters and reflects remaining UV rays. This dual action provides stable, broad-spectrum protection that lasts longer than many traditional filters.

Pros

Excellent photostability

Unlike some chemical filters that degrade quickly, this ingredient stays effective for hours, meaning you get more reliable protection without frequent reapplication.

Gentle on sensitive skin

Its large molecular size means it sits mostly on the skin surface rather than penetrating deeply, which reduces the chance of irritation or allergic reactions.

Cons and cautions

May leave a slight white cast

Although much better than older mineral sunscreens, some formulations can still leave a faint whitish sheen, especially on darker skin tones.

Limited global approval

This filter is not yet approved by the FDA for use in the United States, so you won't find it in American sunscreens, though it's widely used in Europe and Asia.

Best for

  • Anyone looking for a reliable, broad-spectrum sunscreen
  • People with sensitive or reactive skin who want a gentle UV filter

Use caution if

  • Those who prefer only mineral sunscreens (though this is often considered a hybrid)

Usage tips

Apply generously and evenly 15 minutes before sun exposure for best protection.
Reapply every two hours, or after swimming or sweating, to maintain effectiveness.

Safety summary

Extensively tested and considered safe for use in cosmetics at approved concentrations. It has a low irritation profile and is not known to be a significant allergen. The nanoparticle form does not penetrate healthy skin in meaningful amounts.

Research notes

Multiple studies confirm its high photostability and broad-spectrum efficacy. It is one of the most effective UVA filters available. Research also supports its low skin penetration and minimal irritation potential.

Common label clues

Typical concentration
Up to 10% in finished products
Regulatory status
Approved in the EU, Australia, and many Asian countries at concentrations up to 10%. Not FDA-approved in the United States as of 2025.
Common uses
Sunscreens, Moisturizers with SPF, BB creams, Tinted sunscreens
Environmental note
Nanoparticle forms of UV filters have been studied for potential environmental impact, but current evidence suggests this ingredient poses low risk to aquatic life when used as directed.

Good to know

  • This ingredient is often listed as 'Methylene Bis-Benzotriazolyl Tetramethylbutylphenol (Nano)' on labels.
  • It is frequently combined with other UV filters to achieve very high SPF ratings.

Common questions

What is Methylene Bis-Benzotriazolyl Tetramethylbutylphenol (Nano) Copolymer in beauty products?

This ingredient is a sunscreen agent that works like a tiny shield on your skin. It both absorbs harmful UV rays and scatters them like a mirror, giving you broad protection against UVA and UVB. Because it's made of very small particles, it spreads evenly and doesn't leave a heavy white layer like some older sunscreens.

What does Methylene Bis-Benzotriazolyl Tetramethylbutylphenol (Nano) Copolymer do in a beauty product?

When applied to skin, the particles form a thin, even film. The organic part absorbs UV energy and converts it into harmless heat, while the polymer structure scatters and reflects remaining UV rays. This dual action provides stable, broad-spectrum protection that lasts longer than many traditional filters.

Is Methylene Bis-Benzotriazolyl Tetramethylbutylphenol (Nano) Copolymer safe for most people?

Extensively tested and considered safe for use in cosmetics at approved concentrations. It has a low irritation profile and is not known to be a significant allergen. The nanoparticle form does not penetrate healthy skin in meaningful amounts.

Who should be careful with Methylene Bis-Benzotriazolyl Tetramethylbutylphenol (Nano) Copolymer?

Those who prefer only mineral sunscreens (though this is often considered a hybrid)

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.