Octinoxate
Chemical UVB filter (ethylhexyl methoxycinnamate). Estrogenic endocrine-disruptor signals. Avoided in pregnancy.
Quick answer
Avoid octinoxate during pregnancy. The most-used chemical UVB filter globally, with estrogenic endocrine-disruptor signals in animal and cell studies. Flagged alongside oxybenzone in mainstream pregnancy guidance. Switch to mineral SPF.
INCI name
Ethylhexyl Methoxycinnamate
CAS number
5466-77-3
Also known as
Octinoxate, octyl methoxycinnamate, OMC, EHMC, 2-ethylhexyl 4-methoxycinnamate
Formula
C18H26O3
What is Octinoxate?
What octinoxate is
Octinoxate (ethylhexyl methoxycinnamate, EHMC, OMC) is the most widely used chemical UVB filter in sunscreens globally. It absorbs UVB radiation (280–320 nm) and is found in roughly half of all chemical sunscreens, plus many cosmetics, lip products, and “anti-aging” moisturizers that include SPF1.
Like oxybenzone, it’s banned in Hawaii (effective 2021) over reef-toxicity, and many brands have voluntarily reformulated.
Why octinoxate is avoided in pregnancy
Octinoxate has demonstrated estrogenic activity in numerous in-vitro and animal studies, including:
- Binding to estrogen receptors at low concentrations
- Effects on thyroid hormone signaling in rats
- Detectable concentrations in human breast milk after topical application2
- Significant systemic absorption confirmed in the 2020 FDA Maximal Usage Trial3
Pregnancy-specific cohort studies are limited, but the combination of estrogenic activity, placental crossing potential, and the existence of safe alternatives makes octinoxate a precautionary “avoid” in pregnancy4.
Why it’s especially common
Octinoxate is liquid at room temperature, cosmetically elegant (no white cast, light feel), and stabilizes other UV filters — making it the default UVB choice for most chemical-sunscreen formulations. Many “facial sunscreens” and “anti-aging” moisturizers with SPF contain octinoxate by default. Read the OTC drug facts panel to identify it.
Pregnancy-safe alternatives
For UVB protection in pregnancy: zinc oxide (broad-spectrum mineral filter) is preferred. Titanium dioxide provides UVB-skewed coverage and pairs well with zinc for broad-spectrum protection. Both are FDA-designated GRASE5.
Is Octinoxate safe while breastfeeding?
Avoid octinoxate during breastfeeding — detectable in breast milk after maternal use.
When to talk to your OB
If you used a product containing Octinoxate 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. Ethylhexyl methoxycinnamate. PubChem. View source →
- Schlumpf M, Schmid P, Durrer S, et al. (2004). Endocrine activity and developmental toxicity of cosmetic UV filters. Toxicology. 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 →
- Krause M, Klit A, Blomberg Jensen M, et al. (2012). Sunscreens: are they beneficial for health?. International Journal of Andrology. View source →
- U.S. Food and Drug Administration. (2021). Sunscreen monograph. FDA. View source →