Oxybenzone

What is Oxybenzone?

What oxybenzone is

Oxybenzone (benzophenone-3) is a chemical UV filter that absorbs UVB and short-wavelength UVA light, converting the energy to heat. It’s been widely used in sunscreens since the 1980s and was once the most common chemical filter in U.S. products1.

Hawaii banned oxybenzone in 2021 over reef-toxicity concerns, and several other jurisdictions have followed. Many U.S. brands have reformulated to omit it.

Why oxybenzone is avoided in pregnancy

Oxybenzone is an established endocrine disruptor. It binds estrogen receptors at low concentrations and demonstrates anti-androgenic effects in laboratory assays2. More importantly for pregnancy:

• Systemic absorption is substantial. A 2020 FDA Maximal Usage Trial demonstrated that oxybenzone reaches plasma concentrations above the FDA’s 0.5 ng/mL safety threshold after a single application3.
• It crosses the placenta. Studies have detected oxybenzone in maternal serum, cord blood, and amniotic fluid — confirming fetal exposure4.
• Cohort studies show associations. Higher maternal urinary oxybenzone has been linked to altered birth weight in male infants and an increased risk of Hirschsprung disease (a congenital colorectal condition)2.

The cumulative evidence doesn’t prove harm at typical exposure levels, but it is more than enough to warrant precautionary avoidance during pregnancy.

Where oxybenzone appears

Most commonly in chemical-filter sunscreens, especially older or budget formulations. Less common in “mineral” or “reef-safe” SPF products. Check the active ingredients on the OTC drug facts panel — oxybenzone will be listed by name with a percentage.

Safer pregnancy sunscreen choices

The preferred pregnancy SPF actives are zinc oxide and titanium dioxide — both physical filters that sit on top of skin with minimal systemic absorption. The FDA has proposed only these two as “Generally Recognized as Safe and Effective” (GRASE) for sunscreen use5.