The science behind the light

Red and near-infrared light have been studied for decades, under names including photobiomodulation (PBM), low-level light therapy (LLLT) and low-level laser therapy.

Researchers have looked at how particular wavelengths of light interact with the body's cells, and at their uses in areas such as musculoskeletal health, exercise recovery and skin.

Evidence, not promises

The research is substantial, but it isn't uniform. Results depend on wavelength, power, dose, session time and how the light is used. Some studies show clear benefits for specific uses; others show little or no effect. That is normal in a developing field, and it is why using the right settings for the right purpose matters.

&Recover looks at the research, the technology and how a device is actually used. Below is a selection of the studies we follow, with a plain-English summary of each.

Research areas

PhotobiomodulationCellular energyExercise & recoveryMusculoskeletal healthSkin & collagen

How light interacts with cells

Hamblin MR (2018). Mechanisms and mitochondrial redox signaling in photobiomodulation. Photochemistry and Photobiology, 94(2), 199–212. doi:10.1111/php.12864

A widely cited review of how red and near-infrared light is thought to act on cells, with a focus on mitochondria (the parts of the cell that produce energy) and the signalling that follows.

Exercise and recovery

Leal-Junior ECP et al. (2015). Effect of phototherapy (low-level laser therapy and light-emitting diode therapy) on exercise performance and markers of exercise recovery: a systematic review with meta-analysis. Lasers in Medical Science, 30(2), 925–939. doi:10.1007/s10103-013-1465-4

A review combining controlled trials of light applied around exercise, looking at performance and recovery markers.

Nampo FK et al. (2016). Low-level phototherapy to improve exercise capacity and muscle performance: a systematic review and meta-analysis. Lasers in Medical Science, 31(9), 1957–1970. doi:10.1007/s10103-016-1977-9

16 trials, 297 participants. Laser applied before exercise was linked with more repetitions, longer time to exhaustion and lower blood lactate. The two LED-only trials showed no clear difference from placebo. The authors rated the evidence quality as limited.

Morgan RM et al. (2024). Effects of photobiomodulation on pain and return to play of injured athletes: a systematic review and meta-analysis. Journal of Strength and Conditioning Research, 38(6), e310–e319. doi:10.1519/JSC.0000000000004752

A review of studies in athletes. Limited evidence suggested light therapy did not shorten time to return to play after injury.

Álvarez-Martínez M, Borden G (2025). A systematic review on whole-body photobiomodulation for exercise performance and recovery. Lasers in Medical Science, 40, 55. doi:10.1007/s10103-025-04318-w

Five studies, 105 active participants. Whole-body light beds did not improve exercise performance or recovery. The authors note that targeted (localised) use has a larger research base.

Skin

Lee SY et al. (2007). A prospective, randomized, placebo-controlled, double-blinded, and split-face clinical study on LED phototherapy for skin rejuvenation. Journal of Photochemistry and Photobiology B, 88(1), 51–67. doi:10.1016/j.jphotobiol.2007.04.008

76 participants, twice weekly for four weeks, using 633 nm and 830 nm light. Measured wrinkles were reduced by up to 36% and skin elasticity increased by up to 19% compared with baseline, with no side effects reported.

Wunsch A, Matuschka K (2014). A controlled trial to determine the efficacy of red and near-infrared light treatment in patient satisfaction, reduction of fine lines, wrinkles, skin roughness, and intradermal collagen density increase. Photomedicine and Laser Surgery, 32(2), 93–100. doi:10.1089/pho.2013.3616

136 volunteers. After 30 sessions, the treated groups showed improved skin tone and feel, reduced roughness and higher collagen density on ultrasound compared with controls. Red-only light worked as well as broader-spectrum light.

This page summarises published research for general information. It is not medical advice, and the results of individual studies do not guarantee any particular result from a specific device. Last updated October 2026. Questions? Get in touch.