Avobenzone
Chemical UVA filter. Demonstrated systemic absorption in FDA trials; long-term effects unknown. Use cautiously in pregnancy; mineral filters preferred.
Quick answer
Use avobenzone cautiously in pregnancy. The FDA Maximal Usage Trial confirmed it reaches plasma concentrations above the safety threshold after a single application. Long-term effects of systemic exposure are unknown. Mineral sunscreens are the safer first-choice.
INCI name
Butyl Methoxydibenzoylmethane
CAS number
70356-09-1
Also known as
Avobenzone, BMDBM, Parsol 1789
Formula
C20H22O3
What is Avobenzone?
What avobenzone is
Avobenzone (butyl methoxydibenzoylmethane) is the most common chemical UVA filter in U.S. and European sunscreens. It absorbs across the full UVA range (320–400 nm), providing the long-wavelength UV protection that older formulations lacked1.
Without avobenzone (or comparable UVA actives), most chemical sunscreens would offer mainly UVB protection — insufficient for full broad-spectrum coverage. As a result, avobenzone appears in nearly every modern chemical sunscreen on the market.
Why avobenzone is caution-rated in pregnancy
Unlike oxybenzone and octinoxate (which have clearer endocrine signals), avobenzone hasn’t demonstrated strong hormonal effects in laboratory studies. But the 2020 FDA Maximal Usage Trial showed that avobenzone reaches plasma concentrations above the FDA’s 0.5 ng/mL threshold after a single application of conventional sunscreen2. The FDA has placed avobenzone (along with several other chemical filters) in the “more safety data needed” category — not GRASE-affirmed.
Pregnancy-specific data are essentially absent. Avobenzone is also notoriously unstable in sunlight, degrading into breakdown products whose safety is even less studied. This is why avobenzone is often combined with stabilizers like octocrylene3.
A pragmatic pregnancy approach
If your existing sunscreen contains avobenzone but no oxybenzone or octinoxate, switching to mineral SPF is the safer choice but not urgent. The protection from any reputable SPF is better than skipping sunscreen — sun damage and melasma (the “pregnancy mask”) are real concerns too.
If you’re buying a new sunscreen during pregnancy, choose a mineral formula with zinc oxide and/or titanium dioxide — both FDA-designated GRASE with negligible systemic absorption4.
Sunscreen ingredients to prioritize avoiding
The strongest pregnancy “avoid” list is oxybenzone and octinoxate (both endocrine-active). Avobenzone, homosalate, and octocrylene are second-tier “caution” choices — not as clearly problematic but better swapped if convenient.
When to talk to your OB
If you used a product containing Avobenzone before learning you were pregnant, mention it at your next prenatal visit — but most topical cosmetic exposures are not a cause for panic. For prescription exposures or specific concerns, contact your OB or midwife directly.
Sources
- U.S. National Library of Medicine. Avobenzone. PubChem. View source →
- Matta MK, Florian J, Zusterzeel R, et al. (2020). Effect of sunscreen application on plasma concentration of sunscreen active ingredients. JAMA. View source →
- Schwack W, Rudolph T. (1995). Photochemistry of dibenzoyl methane UVA filters. Journal of Photochemistry and Photobiology B. View source →
- U.S. Food and Drug Administration. (2021). Sunscreen Drug Products for OTC Human Use — Final Order. FDA. View source →