Question 1

What is Methylene Bis-Benzotriazolyl Tetramethylbutylphenol and what does it do in sunscreen?

Accepted Answer

Methylene Bis-Benzotriazolyl Tetramethylbutylphenol is a modern broad-spectrum UV filter sold under the trade name Tinosorb M. It is a hybrid filter that both absorbs and scatters UV light across the UVB and UVA range. Because it is photostable and water-dispersible, it gives strong, durable protection and is often used to round out broad-spectrum cover.

Question 2

Is Methylene Bis-Benzotriazolyl Tetramethylbutylphenol a UVA or UVB filter?

Accepted Answer

Both. It is a broad-spectrum filter, covering UVB and into the UVA range in a single ingredient, which is part of why formulators like it. It is also photostable, meaning it does not break down quickly in sunlight, and it can help stabilize less robust filters in the same formula. Sunscreens still pair it with other filters to fine-tune the overall protection.

Question 3

Is Methylene Bis-Benzotriazolyl Tetramethylbutylphenol safe?

Accepted Answer

It is regarded as a well-tolerated, low-irritation filter. It is a large, photostable molecule that shows very low skin penetration, sitting largely on the surface where it does its work. It is approved for sunscreens in the EU, UK, Asia and many other markets, but it is not currently approved for US OTC sunscreens, which reflects a regulatory backlog rather than a safety problem.

Question 4

Why is Methylene Bis-Benzotriazolyl Tetramethylbutylphenol not in US sunscreens?

Accepted Answer

Because it has not yet been approved for over-the-counter sunscreens in the United States, where the list of allowed UV filters has not been updated in decades. It is widely used in Europe, the UK and Asia, so its absence from US products is a regulatory backlog, not a safety finding. This is the same reason several other modern filters like Tinosorb S are missing from US labels.

Question 5

Is Methylene Bis-Benzotriazolyl Tetramethylbutylphenol natural?

Accepted Answer

No, it is a modern synthetic UV filter made in a lab, not found in nature. Synthetic here simply means it was engineered for strong, photostable, broad-spectrum protection. That design is exactly why it performs well, and it says nothing about safety either way.

Question 6

Does Methylene Bis-Benzotriazolyl Tetramethylbutylphenol clog pores?

Accepted Answer

Generally no. It is a UV filter used at controlled levels rather than a heavy oil or wax, so it is not a typical pore-clogging ingredient. As always, how a finished sunscreen feels on blemish-prone skin depends far more on the emollients and texturizers around it than on the filter itself.

Methylene Bis-Benzotriazolyl Tetramethylbutylphenol

What Methylene Bis-Benzotriazolyl Tetramethylbutylphenol is & what it does