What it is
Butyl methoxydibenzoylmethane, commonly called avobenzone, is an oil-soluble dibenzoylmethane derivative and one of the few widely available organic filters that absorbs across essentially the full UVA range, with peak absorption near 357-360 nm. Its main drawback is photoinstability: it can lose a large share of its UV-absorbing capacity after about an hour of sunlight, reported around a 36% drop. To counter this, it is generally formulated with stabilizing partners such as octocrylene, and in some products with filters like Tinosorb S or ensulizole, or via encapsulation. It provides little UVB protection on its own and is used as the UVA component of a multi-filter system.
Spectrum coverage
UVA1 · UVA2
Regional approval · max %
Safety & warnings
Avobenzone is generally considered non-irritating and is one of the most widely used UVA filters, with sources noting no estrogenic activity. Its main practical limitation is chemical stability rather than tolerability, which is why it is combined with stabilizing filters. Rare contact or photocontact allergy to sunscreen filters can occur, so anyone with a history of reactions to sunscreens should patch test and seek advice if needed.
Origin & sourcing
Avobenzone is a synthetic organic compound, a dibenzoylmethane derivative bearing a tert-butylphenyl group and a methoxyphenyl group. It is produced by chemical synthesis and does not occur naturally.
History
Avobenzone was patented in 1973 and later approved by the US Food and Drug Administration in 1988, after which it became a mainstay UVA filter in broad-spectrum sunscreens.
Questions everyone asks
Is avobenzone the same as butyl methoxydibenzoylmethane?
Yes. Butyl methoxydibenzoylmethane is the INCI name, and avobenzone is its common name; trade names include Parsol 1789.
Why does avobenzone need other filters with it?
It degrades in sunlight, losing a large part of its UV absorption within about an hour, so it is paired with stabilizers such as octocrylene to keep it working.
What does avobenzone protect against?
It is a UVA filter that absorbs across the UVA range, with peak absorption around 357 nm, and provides little UVB protection by itself.