Ingredient review
Terephthalylidene Dicamphor Sulfonic Acid
INCI: Terephthalylidene Dicamphor Sulfonic Acid
A highly photostable, broad-spectrum UVA filter that offers reliable sun protection with a low irritation profile.
In plain English
This is a man-made sunscreen ingredient that absorbs ultraviolet A (UVA) rays, which are the type of sunlight that can cause premature aging and deeper skin damage. It's often used alongside other sun filters to provide balanced protection without breaking down quickly in the sun.
Review score
Safety, usefulness, and evidence
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
Quick decision guide
Easy yes for most routines
Terephthalylidene Dicamphor Sulfonic Acid 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 Terephthalylidene Dicamphor Sulfonic Acid.
- 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
strongThere is a stronger practical or research basis for the ingredient role described here.
What it is
A synthetic organic compound derived from camphor and benzylidene chemistry, designed specifically as a UVA filter. It is water-soluble and remains stable under sunlight, meaning it doesn't degrade rapidly like some older sunscreens.
How it works
It absorbs UVA radiation (320–400 nm) and converts it into harmless heat, preventing the rays from penetrating deeper layers of the skin. Its molecular structure is very stable, so it continues to protect for longer periods without needing frequent reapplication.
Pros
Excellent UVA protection
It specifically targets UVA rays, which are linked to wrinkles and skin aging, giving you more comprehensive sun defense.
Stays effective in sunlight
Unlike some chemical filters that break down after an hour, this ingredient remains stable, so your protection lasts longer between applications.
Cons and cautions
Needs UVB partners
It doesn't cover UVB rays well on its own, so it's always combined with other sunscreen ingredients to ensure full protection.
Potential white cast
At higher concentrations, it can leave a slight whitish residue on darker skin tones, though less than mineral sunscreens.
Best for
- Anyone seeking high UVA protection, especially for anti-aging
- People with sensitive skin who react to other chemical filters
- Those who spend extended time outdoors and need long-lasting protection
Use caution if
- Individuals with known allergy to camphor derivatives (rare)
- Those who prefer purely mineral sunscreens
Usage tips
Safety summary
Extensively tested and considered safe for use in sunscreens at regulated concentrations. It has a low irritation and allergy profile, making it suitable for sensitive skin. No significant systemic absorption concerns have been raised in human studies.
Research notes
Multiple peer-reviewed studies confirm its photostability and efficacy as a UVA filter. It is often cited as a benchmark for UVA protection due to its stability and safety record.
Common label clues
- Typical concentration
- Up to 10% in finished products (regulated limit)
- Regulatory status
- Approved as a UV filter in the EU, Canada, Australia, and many other countries. In the US, it is not yet generally approved by the FDA but may appear in products under a Time and Extent Application (TEA) or in sunscreens marketed abroad.
- Common uses
- Sunscreens, Moisturizers with SPF, Day creams
- Environmental note
- Studies suggest this ingredient has low potential for coral reef toxicity compared to some other chemical filters like oxybenzone, but more research is ongoing.
Good to know
- This ingredient is approved in the EU, Canada, and Australia, but not yet fully approved by the FDA in the US (though it's used in some formulations under special permissions).
- It is often listed as 'Ecamsule' or 'Mexoryl SX' on product labels.
Common questions
What is Terephthalylidene Dicamphor Sulfonic Acid in beauty products?
This is a man-made sunscreen ingredient that absorbs ultraviolet A (UVA) rays, which are the type of sunlight that can cause premature aging and deeper skin damage. It's often used alongside other sun filters to provide balanced protection without breaking down quickly in the sun.
What does Terephthalylidene Dicamphor Sulfonic Acid do in a beauty product?
It absorbs UVA radiation (320–400 nm) and converts it into harmless heat, preventing the rays from penetrating deeper layers of the skin. Its molecular structure is very stable, so it continues to protect for longer periods without needing frequent reapplication.
Is Terephthalylidene Dicamphor Sulfonic Acid safe for most people?
Extensively tested and considered safe for use in sunscreens at regulated concentrations. It has a low irritation and allergy profile, making it suitable for sensitive skin. No significant systemic absorption concerns have been raised in human studies.
Who should be careful with Terephthalylidene Dicamphor Sulfonic Acid?
Individuals with known allergy to camphor derivatives (rare) Those who prefer purely mineral sunscreens
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.