Visible blue light has been identified as an additional contributor to cutaneous photoaging. There exists a need for active ingredients to significantly protect against blue light-induced hyperpigmentation. 

A recent study published in the International Journal of Cosmetic Science reported that aimed to detect visible changes in skin pigmentation following repeated irradiation of the skin with LED-based blue light and to reduce pigmentation using suitable active ingredients.

This was a randomized, double-blinded and placebo-controlled clinical study on 33 female volunteers with skin phototypes III and IV. Here, a repetitive blue light (4 × 60 J cm^-2, 450 nm) irradiation protocol was used on the volunteers inner forearms. 

The findings revealed significant changes in chromophore status – of melanin, hemoglobin and oxygen saturation, immediately after blue light irradiation. Additionally, visible skin color changes were observed – evident through a significant decrease in ITA° values and an increase in a*, 24 h post-irradiation. While hyperpigmentation and skin reddening were mitigated by both, a formulation containing 3% of a microalgal product and a formulation containing 3% niacinamide.

The results provide evidence that extract of the microalga Scenedesmus rubescens and niacinamide (vitamin B3) have the potential to protect against blue light-induced hyperpigmentation.

Source: International Journal of Cosmetic Science. 2020 Aug;42(4):399-406. doi: 10.1111/ics.12637.