THE CURE INDEX
Helio Cure's evidence score based on human clinical trials for red light therapy.
Multiple sclerosis (MS) is a condition in which the immune system damages the protective covering of nerve fibers, disrupting movement, sensation, and vision.
Across 4 human studies covering 151 participants, red light therapy showed mixed evidence for multiple sclerosis. The CURE Index rated this condition 37 out of 100, indicating limited confidence.
Patients reported gains in muscle strength and daily function with red light therapy, though the studies disagreed on whether fatigue improved.
All 4 studies were randomized controlled trials, out of which 1 reported an effective outcome, 2 reported partially effective outcomes, and 1 found no significant benefit.
The studies used wavelengths from 600 to 1100 nm, with 600 nm and 1100 nm reported as most cited. Sessions were given 4 to 24 times, over 14 to 84 days lasting from 30 seconds to 6 minutes.
EVIDENCE AT A GLANCE
The numbers behind the verdict.
MOST CITED WAVELENGTHS
The wavelengths appearing most often in studies that showed benefit for multiple sclerosis.
600 nm · 1100 nmTREATMENT PROTOCOL RANGES
The lowest and highest values used across multiple sclerosis studies.
| PARAMETER | RANGE |
|---|---|
| Wavelength | 600-1100 nm |
| Session Duration | 30 seconds-6 minutes |
| Session Frequency | 4-24 per week |
| Therapy Duration | 14-84 days |
Note: We have excluded meta-analyses and reviews from scoring, but the list of human studies below contains them for your reference.
5 Human Studies on Red Light Therapy for Multiple Sclerosis
Review Linked Photobiomodulation to Better Function in Multiple Sclerosis
Across 8 studies published between 2012 and 2024, a 2024 systematic review examined what researchers have found about photobiomodulation (PBM) for multiple sclerosis (MS). The review searched 2 research databases and screened 126 articles down to the 8 that met its criteria, covering wavelengths from 640 to 905 nm, irradiance from 33 to 1780 mW/cm², and doses from 3 to 287 J/cm². The review concluded that PBM appeared to shift brain markers linked to inflammation, cell stress, and cell death, and that movement, sensation, and thinking improved in people with MS after treatment. No study included in the review reported adverse effects from PBM.
- Study Type
- Review
- Treated Area
- Head And Muscles
- Wavelength(s)
- 640, 650, 660, 670, 808, 830, 875, 904, 905 nm
- Session Duration
- 20 seconds, 30 seconds, 3 minutes, 5 minutes, 6 minutes, 10 minutes, 15 minutes, 40 minutes
- Session Frequency
- 4, 6, 7, 21, 24, 30 per week
Study Title: Systematic review of photobiomodulation for multiple sclerosis.
Combining Laser and Magnetic Therapy Improved Daily Function in Multiple Sclerosis
120 adults with multiple sclerosis (MS), 82 women and 38 men aged 21 to 81, took part in a 2016 randomized controlled trial in Poland testing laser therapy as part of a rehabilitation program. Participants were divided into 4 treatment groups, with light at 620 to 780 nm applied in contact to the upper and lower spine at 50 mW, 3 J, and 3 J/cm² for 30 seconds per session across 21 days of treatment. Scores measuring movement ability and independence in daily activities appeared to improve in all 4 groups, with the combination of laser therapy and magnetic therapy producing the largest gains. Those gains were still present 30 days after treatment ended.
- Study Type
- Randomized Controlled Trial
- Participants
- 120
- Treated Area
- Spine
- Wavelength(s)
- 620-780 nm
- Distance
- Contact
- Session Duration
- 30 seconds
- Session Frequency
- 21 per week
- Therapy Duration
- 21 days
Study Title: Application of laser radiation and magnetostimulation in therapy of patients with multiple sclerosis.
Higher Light Dose Improved Muscle Force Recovery in Multiple Sclerosis
Energy doses of 40, 80, and 120 J were tested against a placebo in a 2024 double-blind crossover randomized controlled trial of photobiomodulation therapy (PBMT) for muscle weakness in multiple sclerosis (MS). 17 adults with MS who were able to walk, 14 of them women, received light at 600 to 1100 nm applied to the muscle at the front of the shin, and 12 of them went on to a second stage at a university in Milwaukee, United States, in which an individually chosen dose was given across 4 sessions over 14 days. According to the trial, only the higher single dose produced better recovery of muscle force than the placebo, at 101.89% against 96.3%. Maximum strength rose from 162.70 to 185.56 newtons, a measure of force, after the 2-week individually chosen dose. Endurance and muscle fatigue did not improve with either the active treatment or the placebo.
- Study Type
- Randomized Controlled Trial
- Participants
- 17
- Treated Area
- Lower Leg
- Wavelength(s)
- 600-1100 nm
- Session Frequency
- 4 per week
- Therapy Duration
- 14 days
Study Title: Effects of photobiomodulation therapy on muscle function in individuals with multiple sclerosis.
Anti-Inflammatory Blood Marker Increased After Photobiomodulation in MS
Comparing light delivered under the tongue against light delivered over a blood vessel at the wrist, a 2020 randomized controlled trial examined photobiomodulation (PBM) in multiple sclerosis (MS) that flares up and then eases. 14 people with a disability score of up to 6.0 on a standard MS rating scale received 808 nm light at 100 mW, 800 mW/cm², 36.05 J and 287 J/cm², delivered for 6 minutes per session twice a week across 24 sessions over 84 days. The trial found that a blood marker that helps calm inflammation rose from 2.8 to 8.3 pg/ml in the under-the-tongue group and from 2.7 to 11.7 pg/ml in the wrist group. A second blood marker linked to the disease process did not change in either group.
- Study Type
- Randomized Controlled Trial
- Participants
- 14
- Treated Area
- Mouth And Arm
- Wavelength(s)
- 808 nm
- Session Duration
- 6 minutes
- Session Frequency
- 24 per week
- Therapy Duration
- 84 days
Study Title: Effects of photobiomodulation on interleukin-10 and nitrites in individuals with relapsing-remitting multiple sclerosis - Randomized clinical trial.
No Change in Multiple Sclerosis Fatigue After Photobiomodulation
No reduction in fatigue followed treatment in a 2022 randomized controlled trial of photobiomodulation (PBM) for multiple sclerosis (MS) that flares up and then eases. Participants recruited from a university health clinic in São Paulo, Brazil, were randomly assigned to 2 groups, 1 receiving 808 nm light at 36 J under the tongue and the other receiving the same light over a blood vessel at the wrist, for 6 minutes per session. Scores on a standard questionnaire measuring how much fatigue affected daily life did not appear to differ meaningfully between the 2 groups, either overall or on its individual sections.
- Study Type
- Randomized Controlled Trial
- Treated Area
- Mouth, Arm
- Wavelength(s)
- 808 nm
- Session Duration
- 6 minutes
Study Title: Effect of photobiomodulation on fatigue in individuals with relapsing-remitting multiple sclerosis: a pilot study.
The CURE Index (Clinical Understanding of Red-light Evidence) by Helio Cure is a 0-100 evidence score based on published human clinical trials. Higher scores mean stronger evidence. Read full methodology →
Data is powered by AI and reviewed by the Helio Cure team.
This page is for educational purposes only. Not medical advice. Consult a healthcare provider before starting red light therapy. Helio Cure does not diagnose, treat, or cure any medical condition.
Last updated: Oct 12, 2026