UVB radiation is predominantly absorbed in the epidermis, affecting keratinocytes and melanocytes, while UVA radiation penetrates deeply and interacts with both epidermal cells and dermal fibroblasts. Both UV and visible light generate reactive oxygen species (ROS). It is known that ROS are formed during an inflammatory reaction resulting from excessive exposure to sunlight, such exposure can also cause erythema, burning, tanning, photoaging and skin cancer. The daily use of sunscreens, which are formulated with inorganic and organic UV filters, is a preventive measure. There are reports about the toxicity and allergenicity of organic UV filters, which can even cause harmful effects on the environment. Such demands suggest the search for natural UV filters. Among the promising alternatives, bixin, an annatto carotenoid, and Bixa orellana extract stand out. Carotenoids have anti-erythematous and antioxidant properties, so it is expected that bixin can quench ROS. Therefore, the objective of this study was to verify the antioxidant potential of bixin through a multicenter in vitro experiment on the suppression of reactive oxygen species by bixin in fibroblast culture. Previously, the pigments were extracted from annatto seeds at IQ-USP, as well as characterized by mass spectrometry, infrared spectroscopy and UV-visible spectrometry. At NIB-UMC, culture and cell viability of HFF human fibroblasts were performed, followed by ROS inhibition experiments. It was observed that there was 41.31% inhibition of ROS formation in HFF cells treated with bixin. It is concluded that bixin has antioxidant potential, promoting the suppression of reactive oxygen species verified by fluorescence microscopy.