A Malaga Lab Adds Rooibos to Sunscreen and Finds the Filters Last Longer
University of Malaga researchers found rooibos extract raised sun protection factor by up to 50 percent and slowed the breakdown of standard UV filters. The work is laboratory-only, not yet tested on skin.
Researchers at Spain's University of Malaga have added rooibos extract to standard sunscreen filters and found the combination holds up better under light than the filters do alone.
The Laboratory of Dermatological Photobiology, working with Cantabria Labs Espana, tested the red bush's extract alongside conventional UV filters and measured up to a 50 percent increase in sun protection factor over the filters on their own. The extract also slowed photodegradation, the process by which sunscreen's active ingredients break down under sunlight and stop working partway through a day at the beach.
Jose Aguilera of the university's Skin Cancer group and Maria Victoria de Galvez, of the Department of Medicine and Dermatology, led the work. "The attenuation under light exposure is one of the problems of traditional sunscreens," de Galvez said, describing the degradation the rooibos extract appears to slow. The findings appeared in Photochemical and Photobiological Sciences.
The rooibos does two things at once in the formulation: it filters ultraviolet light directly, and its antioxidant compounds appear to protect the other filters from breaking down as fast. Rooibos is rich in aspalathin and other polyphenols already studied for antioxidant activity in the cup; here they are doing a different job, in a sunscreen jar rather than a kettle.
None of this has left the laboratory. The researchers were plain about it: the work "so far has only been conducted in the laboratory," with no testing on human skin and no finished product to buy. A stronger, longer-lasting sunscreen with rooibos in it is a formulation researchers have shown works on a bench, not a claim about what a bottle on a shelf can do today.
So the standing line holds. Rooibos is caffeine-free and rich in aspalathin, and that is the whole of the claim, whether the cup is the one at the kettle or, one day, the one on a lab bench measuring UV filters.
Sources: Phys.org, More effective, longer-lasting sunscreens from a natural ingredient; EurekAlert, University of Malaga press release; J. Aguilera et al., Photochemical and Photobiological Sciences, DOI: 10.1007/s43630-025-00846-0.