Does avobenzone sunscreen stop working in the sun?

Avobenzone loses much of its UVA protection within an hour without a photostabiliser.

Evidence

Source:: Chatelain E, Gabard B. Photochem Photobiol. 2001;74(3):401-6
Applies to:: Formulations containing butyl methoxydibenzoylmethane
What this does not establish:: How a given product performs on your skin. Finished-product pH and concentration are rarely published, so this describes the chemistry, not a measurement of any specific product.
Last reviewed:: 2026-09-26

In practice

Avobenzone loses a substantial share of its UVA protection within an hour of sun exposure unless it is paired with a photostabiliser such as octocrylene, bemotrizinol or a similar filter. None is listed here, so UVA protection may fall off faster than the SPF figure suggests. Reapplication matters more with this formulation.

Dermasift analyses skincare formulations against published cosmetic science. This is information, not medical advice — for a diagnosed skin condition, speak to a dermatologist.

Check this against a product’s ingredient list

Does avobenzone sunscreen stop working in the sun?

Avobenzone loses much of its UVA protection within an hour without a photostabiliser.

Evidence

Source:: Chatelain E, Gabard B. Photochem Photobiol. 2001;74(3):401-6
Applies to:: Formulations containing butyl methoxydibenzoylmethane
What this does not establish:: How a given product performs on your skin. Finished-product pH and concentration are rarely published, so this describes the chemistry, not a measurement of any specific product.
Last reviewed:: 2026-09-26

In practice

Dermasift analyses skincare formulations against published cosmetic science. This is information, not medical advice — for a diagnosed skin condition, speak to a dermatologist.

Check this against a product’s ingredient list