INGREDIENT · CHEMICAL FILTER
Octinoxate in sunscreen: absorption, stability and safety
Octinoxate is a UVB filter with an endocrine question mark attached. The EU looked at the question recently, reached a surprisingly calm answer, and it still hasn't ended the debate.
You may see it written as
- Ethylhexyl Methoxycinnamate
- Octinoxate
How much gets into the body
In a study of 32 volunteers, daily whole-body application of a cream with 10% each of three filters for a week led to octinoxate blood levels of about 10 ng/mL in women and 20 ng/mL in men. Reproductive hormones including FSH and LH did not change, and the small differences seen in other hormones were not related to sunscreen exposure.1
A 2020 trial tested six ingredients in four sunscreens on 48 volunteers. All six, octinoxate included, passed the 0.5 ng/mL level at which the FDA asks for further safety data, and they did so on the first day after one application.2 That trial measured blood levels, not harm.
Stability: the avobenzone problem
In a lab film of a sunscreen containing avobenzone, oxybenzone and octinoxate, the octinoxate and avobenzone broke down together, faster than expected, and irradiation produced free radicals that persisted after the exposure ended.3
What the EU safety committee said
In 2025 the EU's safety committee gave its opinion on ethylhexyl methoxycinnamate. It said the available evidence shows the substance is endocrine-active, with estrogenic activity and weak anti-androgenic activity in vitro and in vivo. It still considered it safe as a UV filter up to 10% in sunscreen products, including for children, because the margin of safety is high.4
That is a good example of how regulators separate a hazard from a risk. The lab signal is real, but at the exposure levels from normal use, the committee judged the margin large enough. Snifff's 'endocrine-activity signals' note is consistent with that hazard side of the story.
Octinoxate in pregnancy and breastfeeding
Use with caution during pregnancy and lactation: octinoxate has endocrine-activity signals.
Snifff's note is a caution: octinoxate shows endocrine-activity signals. That matches what the EU committee found in lab studies,4 though the committee did not conclude that sunscreen use is unsafe.
We found no pregnancy-specific study of octinoxate, and the 32-person study found no hormone changes linked to the sunscreens, in non-pregnant adults.1 So the caution is about a signal, not a demonstrated effect.
Evidence on cosmetic products in pregnancy is limited overall, so ask your doctor or midwife about the specific product you use.5
What you will see on the label
The names to look for are Ethylhexyl Methoxycinnamate and Octinoxate. In Snifff, it reads as Moderate risk. For the rest of the formula, see what the score means and how to read the list.
As Snifff shows itEthylhexyl Methoxycinnamate
Pregnancy and nursing
Use with caution during pregnancy and lactation: octinoxate has endocrine-activity signals.
Wording as it appears in the extension, which can change between releases.
A FEW MORE ANSWERS
Common questions about octinoxate
Is octinoxate safe?
The EU safety committee judged ethylhexyl methoxycinnamate safe as a UV filter up to 10% in sunscreen products, while noting that it is endocrine-active in lab studies.4
Is octinoxate absorbed into the body?
Yes. Blood levels of about 10 to 20 ng/mL were seen after whole-body use of a cream with 10% of the filter,1 and a 2020 trial found it above the 0.5 ng/mL FDA threshold after one application.2
Is octinoxate an endocrine disruptor?
The EU committee found it endocrine-active in vitro and in vivo, with estrogenic and weak anti-androgenic effects, but judged sunscreen use safe given the margin of safety.4 In the 32-person study, reproductive hormone changes were not related to exposure.1
Is octinoxate safe in pregnancy?
Snifff advises caution because octinoxate shows endocrine-activity signals. We found no pregnancy-specific study, and the EU committee judged sunscreen use safe at up to 10%.4 Ask your doctor or midwife about the product you use.
WHERE THIS COMES FROM
Sources
- Systemic absorption of the sunscreens benzophenone-3, octyl-methoxycinnamate, and 3-(4-methyl-benzylidene) camphor after whole-body topical application and reproductive hormone levels in humansJanjua NR, et al. · Journal of Investigative Dermatology · 2004
- Effect of sunscreen application on plasma concentration of sunscreen active ingredients: a randomized clinical trialMatta MK, et al. · JAMA · 2020
- Unexpected photolysis of the sunscreen octinoxate in the presence of the sunscreen avobenzoneSayre RM, et al. · Photochemistry and Photobiology · 2005
- Opinion on ethylhexyl methoxycinnamate (EHMC)Scientific Committee on Consumer Safety, European Commission · 2025 · Final opinion published 30 June 2025
- Cosmetic dermatology in pregnancy and lactation: a risk-benefit framework for clinical practiceKovacs T, et al. · International Journal of Dermatology · 2026
This page explains an ingredient. It is not medical advice, and it is not an assessment of any product. If you are pregnant, breastfeeding, or have a skin condition, ask your doctor or pharmacist.