WIRED's Reviews team has highlighted red-light therapy devices on discount as part of Nordstrom's Anniversary Sale, which runs until 9 August. The picks draw on more than a year of hands-on testing of LED masks, hats and helmets, a category the outlet says has genuine scientific backing but variable real-world results depending on the device and how it is used.

Featured deals include the Dr. Dennis Gross Spectralite FaceWare Pro in red, reduced to $340 from $455, praised for its short three-minute daily treatment time; the HigherDose Red Light Hat, down to $359 from $449, which testers found effective for stimulating hair regrowth; and the Therabody TheraFace Mask Glo, cut to $300 from $380, a hard-shell mask offering massage via vibrating straps, though testers preferred the discontinued original model. The Omnilux Contour LED Face Mask is not discounted but comes with a free set of hydrogel facial masks worth $29. Reviewers caution that these devices can only stimulate dormant or weakened hair follicles, not reverse permanent hair loss from ageing or alopecia.