Iron oxides in novel skin care formulations attenuate blue light for enhanced protection against skin damage

J Cosmet Dermatol. 2021 Feb;20(2):532-537. doi: 10.1111/jocd.13803. Epub 2020 Nov 18.


Background: Ultraviolet (UV) radiation is a main cause of aging of sun-exposed skin, but greater attention is being focused on the damaging effects of high-energy visible (HEV) light (400 and 500 nm). HEV light exposure has increased with expanding use of consumer electronics, such as smartphones, which have a peak emission in the 400-490 nm range. Sunscreens containing titanium dioxide and zinc oxide protect against UVA and UVB radiation but provide limited protection against HEV light.

Aim: Iron oxides including red iron oxide (Fe2 O3 ), yellow iron oxide (Fe(OH)3 /FeOOH), and black iron oxide (Fe3 O4 ) effectively block HEV light, each with a different attenuation profile. Zinc oxide, titanium dioxide, and iron oxides with patented skin care ingredients have been incorporated into several formulations to provide enhanced skin protection (Colorescience, Inc).

Methods: The percent of HEV light attenuation from 400 nm to 490 nm light was measured in vitro using a technique known as diffuse transmittance spectroscopy using a Perkin Elmer Lambda™ 750 UV/Vis/NIR Spectrophotometer equipped with a 100-mm integrating Labsphere® and PbS detector.

Results: Products formulated with zinc oxide, titanium dioxide, and iron oxides demonstrated 71.9%-85.6% attenuation across the tested wavelengths of 415-465 nm.

Conclusion: Sunscreens formulated with iron oxides provide enhanced protection against blue light, especially when combined with zinc oxide. To our knowledge, similar studies with iron oxides have not been performed.

Keywords: high-energy visible light; iron oxides; photoaging of the skin; photoprotection.

MeSH terms

  • Ferric Compounds
  • Humans
  • Iron
  • Skin
  • Skin Care
  • Sunscreening Agents*
  • Ultraviolet Rays / adverse effects
  • Zinc Oxide*


  • Ferric Compounds
  • Sunscreening Agents
  • ferric oxide
  • Iron
  • Zinc Oxide