Red Light Therapy for Age-Related Muscle Loss: Scientific Evidence

Improvement scores for muscle growth reached 0.58 for active laser photobiomodulation (PBM) therapy and 0.38 for the placebo leg in a 2022 randomized, triple-blind, placebo-controlled trial addressing age-related muscle loss in older women. The trial enrolled 22 women with an average age of 66.6 years, each contributing one leg randomly assigned to active 808 nm PBM at 100 mW and 42 J and the other leg to a placebo laser, alongside supervised resistance training performed 2 times per week for 70 days. The study reported that active PBM was associated with more muscle growth than placebo in this trial.

34 post-menopausal women took part in a 2020 randomized controlled trial evaluating photobiomodulation (PBM) added to resistance training for age-related muscle loss. Both groups trained 2 times per week for 56 days, with the resistance training group of 17 receiving a placebo device and the photobiomodulation group of 17 receiving 630 nm and 850 nm light at 100 mW and 4 J per diode, applied in contact with the front of the thigh for 40 seconds per session. No added improvement in muscle strength was reported for the light therapy group compared to resistance training alone in this trial.

Researchers compared placebo and active photobiomodulation therapy (PBMT) groups in a 2019 randomized double-blinded placebo-controlled trial addressing age-related muscle loss in elderly men. The trial included 24 healthy men aged 60 to 80, split into a placebo group of 13 and an active PBMT group of 11, with both groups completing 84 days of resistance training 2 times per week while an 850 nm laser delivering 240 J per limb was applied to the thighs before each session. The study reported that PBMT did not provide additional benefit over placebo for muscle strength, muscle thickness, or functional capacity in this trial.

A randomized controlled human trial published in 2016 evaluated the effect of low-level laser therapy (LLLT) on muscle performance in elderly women with age-related muscle loss. The 48 participants were split into a control group of 15, a placebo LLLT group of 17 combined with strength training, and an active LLLT group of 16 combined with strength training, using an 808 nm laser applied to the thigh muscles in contact with the skin at 100 mW, 250 J/cm2 fluence, and 35700 mW/cm2 irradiance, for 70 seconds per session, 2 times per week, over 56 days. Researchers reported that LLLT was not effective overall for improving muscle performance in this trial.