Octinoxate

A UV-B filter that absorbs sunlight to protect the skin. Octinoxate (Ethylhexyl Methoxycinnamate) functions as an organic (chemical) ultraviolet (UV) filter primarily by absorbing high-energy UVB radiation (280-320 nm) and some short-wave UVA (UVA-2, 320-340 nm). Its molecular structure allows it to absorb incident UV photons, entering an excited state, and then dissipating this absorbed energy as heat through a photo-isomerization process. This mechanism effectively converts damaging UV radiation into a less harmful form of energy, preventing it from penetrating and causing damage to skin cells, DNA, and contributing to sunburn and photoaging.

Octinoxate is an FDA-approved OTC sunscreen active ingredient. The CIR Expert Panel concluded it is safe as used in cosmetics. It is generally well-tolerated with low potential for skin irritation or sensitization. While some in vitro and animal studies suggest potential endocrine activity at high concentrations, human relevance from topical application is debated, and systemic absorption has been detected in some clinical trials, prompting ongoing FDA review and requests for further data.

Look for products with Up to 7.5% in the US (FDA OTC Monograph); up to 10% in the EU (Cosmetics Regulation). Many formulas utilize it at concentrations up to the maximum allowed (e.g., 7.5% in the US) to achieve desired SPF levels. for clinical efficacy.