Octocrylene

A UV-B filter that absorbs sunlight to protect the skin and stabilizes other sunscreen ingredients. Octocrylene is an organic (chemical) ultraviolet (UV) filter that primarily absorbs UVB and short-wave UVA (UVA-II) radiation. Its molecular structure contains conjugated double bonds which absorb high-energy UV photons, converting the energy into lower-energy heat through intramolecular vibration and rotation, thereby preventing UV-induced DNA damage and oxidative stress in the skin. It also functions as a photostabilizer for other UV filters, notably avobenzone, enhancing their duration of efficacy.

The Cosmetic Ingredient Review (CIR) Expert Panel has assessed Octocrylene as safe for use in cosmetics in the present practices of use and concentration. It is an FDA-approved active ingredient for Over-the-Counter (OTC) sunscreen products. While generally well-tolerated, there are rare reports of allergic contact dermatitis, particularly in individuals with prior sensitization to photoallergens like ketoprofen or benzophenone-3.

Look for products with 2-10% (most formulas use 5-10% as per regulatory limits in the US, EU, Canada, and Australia) for clinical efficacy.