Ingredient review
Di-T-Butyl Hydroxyphenylamino Bisoctylthiotriazine
INCI: DI-T-BUTYL HYDROXYPHENYLAMINO BISOCTYLTHIOTRIAZINE
A highly effective, photostable sunscreen ingredient that provides broad-spectrum protection without common irritation.
In plain English
This is a synthetic sunscreen ingredient that works like a shield on your skin. It absorbs and scatters both UVA (aging) and UVB (burning) rays, helping to prevent sun damage. Unlike some older filters, it stays stable in sunlight and is less likely to cause stinging or irritation, making it a popular choice for sensitive skin.
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
Di-T-Butyl Hydroxyphenylamino Bisoctylthiotriazine 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 Di-T-Butyl Hydroxyphenylamino Bisoctylthiotriazine.
- 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 UV filter that combines two light-absorbing groups into one molecule, giving it broad-spectrum protection and excellent photostability.
How it works
It absorbs UV radiation and converts it into harmless heat, while also scattering some light due to its particle size. This dual action provides consistent protection without breaking down quickly.
Pros
Excellent photostability
Unlike avobenzone, this filter doesn't degrade quickly in sunlight, so your protection lasts longer without needing extra stabilizers.
Gentle on skin
It rarely causes stinging or irritation, making it a good option for sensitive skin types or around the eyes.
Cons and cautions
May leave a white cast
Because it contains microfine particles, it can appear chalky or ashy on medium to dark skin tones, especially at higher concentrations.
Not water-resistant alone
It needs to be combined with film-forming ingredients or other filters to maintain protection after swimming or sweating.
Best for
- Anyone seeking reliable sun protection
- People with sensitive or reactive skin
Use caution if
- Those who prefer mineral-only sunscreens
- Individuals looking for a completely invisible finish on dark skin
Usage tips
Safety summary
Considered safe and effective for use in sunscreens at concentrations up to 10%. It has a low irritation profile and is not known to be a significant allergen or endocrine disruptor.
Research notes
Multiple studies confirm its broad-spectrum efficacy and photostability. It is one of the most well-researched modern UV filters, with strong safety data from regulatory bodies.
Common label clues
- Typical concentration
- Up to 10% in leave-on products
- Regulatory status
- Approved as a UV filter in the EU, Australia, and many other regions; not approved by the FDA for use in the US.
- Common uses
- Sunscreens, Moisturizers with SPF, BB creams
- Environmental note
- Studies suggest it has low toxicity to aquatic life, but as with all sunscreens, it's best to avoid excessive environmental release.
Good to know
- This ingredient is often listed under the trade name Tinosorb M.
- It is approved in many countries worldwide but is not yet FDA-approved for use in the United States.
Common questions
What is Di-T-Butyl Hydroxyphenylamino Bisoctylthiotriazine in beauty products?
This is a synthetic sunscreen ingredient that works like a shield on your skin. It absorbs and scatters both UVA (aging) and UVB (burning) rays, helping to prevent sun damage. Unlike some older filters, it stays stable in sunlight and is less likely to cause stinging or irritation, making it a popular choice for sensitive skin.
What does Di-T-Butyl Hydroxyphenylamino Bisoctylthiotriazine do in a beauty product?
It absorbs UV radiation and converts it into harmless heat, while also scattering some light due to its particle size. This dual action provides consistent protection without breaking down quickly.
Is Di-T-Butyl Hydroxyphenylamino Bisoctylthiotriazine safe for most people?
Considered safe and effective for use in sunscreens at concentrations up to 10%. It has a low irritation profile and is not known to be a significant allergen or endocrine disruptor.
Who should be careful with Di-T-Butyl Hydroxyphenylamino Bisoctylthiotriazine?
Those who prefer mineral-only sunscreens Individuals looking for a completely invisible finish on dark skin
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.