Red Light Therapy for Musculoskeletal Pain: Scientific Evidence

16 out of 19 patients with chronic musculoskeletal pain in 2-joint muscles showed excellent or good improvement in a 2019 observational study on low-level laser therapy (LLLT). Participants were treated at contact distance with 815-845 nm LLLT at 20.1 J/cm2 delivered to the upper arm and gastrocnemius muscles, 16 sessions per week over 56 days. Based on the results, the study suggested that LLLT applied to 2-joint muscles may produce clinically meaningful pain relief in patients with chronic musculoskeletal complaints.

In 2017, a narrative literature review searched PubMed and Web of Science to evaluate low-level laser therapy (LLLT) for a range of rheumatic and orthopedic musculoskeletal conditions. The review described protocols using wavelengths of 600-1,000 nm, including 660, 808, 830, and 904 nm, at irradiances of 1 to 5,000 mW/cm2 and power outputs of 5 to 500 mW, applied 5 to 10 times per week over 10 to 14 days to skin areas, joints, nerves, muscles, and tendons. Positive effects were reported across a range of specific conditions, including neck pain, low back pain, tendon disorders, elbow tendon conditions, rheumatoid arthritis, and osteoarthritis. The therapy was characterized as noninvasive and safe, and the authors recommended further randomized controlled trials to confirm these positive findings.

Compared against control groups, low-level laser therapy (LLLT) produced a statistically significant reduction in musculoskeletal pain across 18 trials in a 2017 systematic review and meta-analysis involving 1,462 adult participants. The review examined LLLT applied at 830 and 904 nm to multiple body sites, including the back, elbow, foot, hand, knee, neck, shoulder, and wrist, and found an overall reduction in pain scores favouring LLLT over control. Researchers reported that studies following World Association of Laser Therapy dosage guidelines showed a larger treatment effect than those that did not, suggesting that adherence to recommended dosing may enhance the effectiveness of LLLT for musculoskeletal pain.

A double-blind randomized controlled trial published in 2016 evaluated the immediate pain relief effect of low-level laser therapy (LLLT) on musculoskeletal sports injuries in college athletes. The 32 participants with motion pain were randomized into an active laser group and a placebo group, with 810 nm LLLT applied at contact distance to the most painful area at 180 mW and 5.4 J per session, once weekly for 10 minutes. Researchers found that LLLT was effective in 75% of the active group compared to 0% of the placebo group, with a pain relief rate of 36.94% versus 8.20%, respectively.

Evidence from 400 studies was synthesized in a 2015 observational review of low-level laser therapy (LLLT) for musculoskeletal pain and related conditions. Protocols described in the review used wavelengths of 660-905 nm, 760-850 nm, and 810 nm at irradiances of 5 to 5,000 mW/cm2 and power outputs of 10-500 mW to 1 W, with sessions of 30 to 60 seconds applied to injury sites, trigger points, tendons, cartilage, and bones. Pain relief, reduced inflammation, and decreased edema were among the benefits reported by the authors across musculoskeletal conditions. Few side effects were reported, and the therapy was described as well-tolerated across patient groups, including the elderly.

Researchers presented a 2015 review of the Biolite device, a patented ultra-low-level laser therapy (ULLLT) system evaluated for musculoskeletal pain and associated impairments across more than 10 years of collected human studies. The device delivered 635 and 650 nm light at 0.015 J/cm2 in short stimulations of 10 to 20 seconds applied to sequences of acupuncture points on the hand, wrist, elbow, and cervical spine at a distance of 1.378 inches, using power outputs of 0.01 to 2 mW at pulse frequencies of 1 and 100 Hz. The authors reported positive effects for musculoskeletal pain across the conditions reviewed, suggesting that ULLLT applied at very low energy levels may offer a treatment option for pain and associated impairments.

When assessed at long-term follow-up rather than immediately after treatment, laser acupuncture was found to produce more consistent benefits for musculoskeletal pain, according to a 2015 systematic review with meta-analysis. Pooled from 49 randomized controlled trials involving 2,360 participants, the review examined laser acupuncture applied to acupuncture points, trigger points, and tender points at wavelengths of 780-860 nm and 904 nm, at fluences of 25, 60, and 105 J/cm2, with sessions ranging from 3 to 15 per week over 7 to 84 days. Moderate-quality evidence was reported in support of laser acupuncture for musculoskeletal pain, with the authors noting that positive effects on both pain and function were more reliably observed at longer follow-up intervals than at the point of treatment cessation.

Whether high-intensity laser therapy (HILT) outperforms low-level laser therapy (LLLT) for musculoskeletal disorders remained unclear after a 2026 systematic review and network meta-analysis searched over 13,882 records and analyzed trials covering knee osteoarthritis, carpal tunnel syndrome, lumbar disc disorders, plantar fasciitis, lateral epicondylitis, neck pain, and shoulder conditions. The included trials used wavelengths of 775 to 1,064 nm at an irradiance of 100 mW/cm2 and fluences of 1.5 to 150 J/cm2, applied at contact distance in sessions of 36 seconds to 15 minutes, delivered 1 to 5 times per week over 14 to 84 days to the knee, wrist, lumbar region, foot, elbow, neck, and shoulder. The review reported that the comparative effectiveness of HILT and LLLT for pain intensity, disability, and range of motion outcomes in musculoskeletal disorders could not be firmly established, and the authors noted that further high-quality trials are needed.

3 therapies were put head-to-head in a 2025 systematic review and meta-analysis of 28 randomized clinical trials involving 1,460 patients with musculoskeletal disorders, comparing extracorporeal shock wave therapy (ESWT), low-level laser therapy (LLLT), and high-intensity laser therapy (HILT). Across the 28 trials, laser therapy was delivered at wavelengths of 685 to 1,064 nm, fluences of 0.0003 to 120 J/cm2, and power outputs ranging from 30 mW to 30 W, with sessions given 4 to 15 times per week at sites including the plantar fascia, elbow, knee, shoulder, heel, and lumbar region. Pain intensity, physical function, strength, range of motion, and quality of life all showed comparable results across ESWT, LLLT, and HILT, leading the authors to suggest that no single approach held a clear advantage for musculoskeletal disorders.

Published in 2025, a systematic review and meta-analysis set out to determine which laser acupuncture parameters drive therapeutic outcomes in musculoskeletal disorders, drawing on 28 randomized controlled trials. Across the 28 trials, laser acupuncture was applied to traditional acupoints, Ashi points, and trigger points using wavelengths of 632.8 to 1,064 nm, irradiances of 10 to 2,800 mW/cm2, and session durations spanning 10 seconds to 20 minutes. Terminology inconsistencies between laser acupuncture and low-level laser therapy, combined with incomplete parameter reporting across studies, were identified as barriers to drawing firm conclusions, and the authors called for new guidelines specifically designed for laser acupuncture research.

2 laser therapy approaches were put head-to-head in a 2024 meta-analysis examining whether high-intensity or low-level laser therapy produced superior outcomes in musculoskeletal disorders. The 12 randomized controlled trials pooled 704 participants with conditions including tennis elbow, carpal tunnel syndrome, chronic low back pain, knee osteoarthritis, plantar fasciitis, and subacromial impingement, using wavelengths spanning 410 to 1,064 nm in sessions of 2 to 10 minutes over 14 to 84 days applied to the lateral elbow, carpal tunnel, low back, knee, plantar fascia, and shoulder. It was reported that there were no statistically significant differences between the 2 therapies in pain, disability, or quality of life outcomes, suggesting that neither approach may hold a clear advantage over the other for musculoskeletal disorders.

86 articles on low-level laser therapy (LLLT) for neuromusculoskeletal conditions were synthesized in a 2020 scoping review that set out to identify how dosage variables affect treatment efficacy. The included studies used wavelengths of 600 to 1,000 nm, irradiances of 5 to 750 mW/cm2, fluences of 1 to 20 J/cm2, and power outputs of 1 mW to 50 W, applied in sessions of 10 seconds to 10 minutes at frequencies of 11 to 13 times per week to the neck, knee, hand, and wrist. The authors identified 7 individual parameters that alter dosage outcomes but reported that high heterogeneity across studies prevented any correlation between dosage variables and treatment efficacy, leaving the relationship between LLLT dose and clinical outcomes in neuromusculoskeletal conditions uncertain.

As early as 1993, an observational study examined why research findings on low-level laser therapy (LLLT) for soft tissue injuries, wounds, and ulcers failed to conclusively support the clinical results being observed in practice. The review described protocols using wavelengths of 500-600, 620-904, 632.8, 770, 890, and 950 nm at fluences of 0.5 to 4 J/cm2 and power outputs of 15 to 60 mW, applied at contact distance 2 times per week at pulse frequencies of 666 to 3,480 Hz. Light quality, probe design, power output, dose, and pulse frequency were identified by the authors as variables likely to have contributed to the mixed findings across studies, with closer attention to these factors recommended for future research.