Methylene Bis-Benzotriazolyl Tetramethylbutylphenol (also known as Bisoctrizole or Tinosorb M) is an organic-particulate UV filter that provides broad-spectrum protection across both UVA and UVB ranges by absorbing and scattering UV radiation. It is photostable and commonly used in sunscreens, often paired with other filters.
| Reported effect | How often | Notes |
|---|---|---|
Skin irritation or contact dermatitis | Rare | Occasional reports of mild irritation, generally considered well-tolerated. |
Allergic contact dermatitis / sensitization | Very rare | Sensitization is uncommon; large molecular size limits skin penetration. |
Frequencies reflect typical cosmetic use reported in the literature, not a guarantee for your skin.
Peer-reviewed papers on this ingredient, via PubMed.