Isoamyl P-Methoxycinnamate
Explained
Isoamyl P-Methoxycinnamate is an oil-soluble chemical UV filter whose main job is to soap up UVB rays (and a tiny bit in the UVA-II range).
It's essentially a cousin of the more common octinoxate. Because it has a cinnamate backbone, it also has some mild antioxidant + free-radical scavenging behavior.
In vitro work measuring its UV-protective efficacy and photostability among 18 EU-approved filters and a peer-review of cosmetic UV filters confirms it performs best as a UVB booster rather than a standalone sunscreen.
Typical use levels sit at or below the EU regulatory cap of 10%, and it usually runs anywhere from 2-10% depending on the target SPF.
This ingredient is approved across the EU, UK, Australia, China, India, and Asia but has not been cleared in the US or Canada yet. This is more of a regulatory backlog situation and not a safety red flag.
See all 185 products with Isoamyl P-Methoxycinnamate
