THE CURE INDEX
Helio Cure's evidence score based on human clinical trials for red light therapy.
Scleroderma is a disease in which the body produces too much collagen, making the skin thicken and harden.
A review of 6 human studies covering 93 participants found red light therapy to be effective for scleroderma. The CURE Index scored this condition 69 out of 100, indicating moderate confidence.
Across studies, red light therapy softened hardened skin, improved movement in the treated area, and reduced pain.
The 6 studies comprised 1 clinical trial and 5 observational studies, of which 5 reported effective outcomes and 1 reported a partially effective outcome.
940 nm, 1064 nm, and 1400 nm were the most cited wavelengths, within a range of 405 nm to 1400 nm. Session length ranged from under 5 minutes to 30 minutes, frequency from 2 to 11 times per week, and total therapy from 21 to 240 days.
EVIDENCE AT A GLANCE
The numbers behind the verdict.
MOST CITED WAVELENGTHS
The wavelengths appearing most often in studies that showed benefit for scleroderma.
940 nm · 1064 nm · 1400 nmTREATMENT PROTOCOL RANGES
The lowest and highest values used across scleroderma studies.
| PARAMETER | RANGE |
|---|---|
| Wavelength | 405-1400 nm |
| Distance | 0.39-3.9 inches |
| Session Duration | 4.73-30 minutes |
| Session Frequency | 2-11 per week |
| Therapy Duration | 21-240 days |
6 Human Studies on Red Light Therapy for Scleroderma
Localized Scleroderma Improved With Home-Use Near Infrared Light
1 woman with linear morphea below her left eye, confirmed by a skin sample, took part in a 2020 observational study of near-infrared photobiomodulation (PBM). She treated the area at home 3 times a week for 240 days, using 920 to 960 nm light at 14 mW/cm² and 4 J/cm², in sessions of 4.73 minutes from a distance of 0.39 inches. The appearance of the skin appeared to improve after the course of treatment. No change in skin texture and no lightening of the skin were reported, despite her darker skin tone.
- Study Type
- Observational Study
- Participants
- 1
- Treated Area
- Face
- Wavelength(s)
- 920-960 nm
- Distance
- 0.39 inches
- Session Duration
- 4.73 minutes
- Session Frequency
- 3 per week
- Therapy Duration
- 240 days
- Study Scope
- Morphea
Study Title: Beneficial Effects of Near-Infrared Light Photobiomodulation in Linear Morphea: A Case Report.
Pulsed Light Outperformed Continuous Wave for Limited Scleroderma Symptoms
Comparing pulsed light against continuous wave light on opposite forearms, a 2014 observational study tested low-level light therapy (LLLT) for the joint and bone symptoms of limited cutaneous systemic sclerosis, once called CREST syndrome. 1 woman aged 34 with a 13-year history of the condition received 940 nm light on both sides, 2 to 3 times a week for 91 days at 60 mW/cm² and 81 J/cm², with the pulsed side treated for 30 minutes and the continuous wave side for 15 minutes, from a distance of 1.42 to 1.73 inches. Both sides appeared to improve in movement and in appearance, and the better result was seen on the pulsed side. The authors concluded that pulsed LLLT represents a treatment alternative for the joint and bone symptoms of limited scleroderma. No adverse effects were noted.
- Study Type
- Observational Study
- Participants
- 1
- Treated Area
- Arm
- Wavelength(s)
- 940 nm
- Distance
- 1.42-1.73 inches
- Session Duration
- 15 minutes, 30 minutes
- Session Frequency
- 2-3 per week
- Therapy Duration
- 91 days
- Study Scope
- Crest Syndrome
Study Title: Pulsed versus continuous wave low-level light therapy on osteoarticular signs and symptoms in limited scleroderma (CREST syndrome): a case report.
Laser-Treated Hand Outperformed the Untreated Hand in Scleroderma
A staggered design treated 1 hand first and left the other untreated as a comparison, in a 2011 observational study of high-peak power laser therapy for scleroderma with Raynaud's phenomenon. 1 woman who had not responded to systemic medications or to surgery received 1064 nm light at 10 to 15 J/cm² and 10 Hz, with a pulse width of 0.30 ms, delivered from a distance of 3.94 inches across 11 sessions. Movement in the treated hand improved after the first session, and paper cuts to that hand did not turn into sores, while a cut to the untreated hand did, the researchers reported. Fingers that had been pale and bluish turned pink after treatment, and Raynaud's attacks became less frequent and less severe. The patient tolerated the treatments well.
- Study Type
- Observational Study
- Participants
- 1
- Treated Area
- Hands
- Wavelength(s)
- 1064 nm
- Distance
- 3.94 inches
- Session Frequency
- 11 per week
Study Title: Scleroderma and raynaud's phenomenon improve with high-peak power laser therapy: a case report.
Water-Filtered Infrared Light Improved Circumscribed Scleroderma in 7 of 10
7 of 10 patients with circumscribed scleroderma showed marked improvement that held up at long-term follow-up, in a 2011 observational study. All 10 had failed to respond to earlier treatments. They received water-filtered infrared A plus visible light (wIRA+VIS) at 580 to 1400 nm, and skin hardness was measured with a device that gauges how hard it has become, in 8 of them and in 10 people without the condition. According to the study, 1 further patient showed less hardening and less active disease, but worsened after treatment stopped. 2 others who had previously failed a form of ultraviolet therapy showed only a slight decrease, and the condition remained active.
- Study Type
- Observational Study
- Participants
- 20
- Treated Area
- Skin
- Wavelength(s)
- 580-1400 nm
- Study Scope
- Cutaneous Scleroderma
Study Title: Irradiation with water-filtered infrared A plus visible light improves cutaneous scleroderma lesions in a series of cases.
Immune Cell Activity Normalized After Infrared Treatment in Scleroderma
Whether near infrared treatment could change immune cell activity was examined in a 2006 observational study of scleroderma. 22 people with scleroderma, 20 age- and sex-matched people without it, and a further group with psoriasis as a second comparison had a blood measure of immune cell activity taken at rest, and again after 2 laboratory substances were used to stimulate the cells. The measure was also taken before and after a course of heating the tissue with infrared light, using 780 to 1400 nm light at 100 mW/cm² in 30-minute sessions over 35 days. The study found that the measure was slightly lower than expected in both disease groups at the start, and that treatment brought it back towards normal in 1 type of immune cell but not in a second type. That shift in the first cell type lasted for 6 weeks after treatment ended.
- Study Type
- Observational Study
- Participants
- 62
- Treated Area
- White Blood Cells
- Wavelength(s)
- 780-1400 nm
- Session Duration
- 30 minutes
- Session Frequency
- 10 per week
- Therapy Duration
- 35 days
Study Title: Neutrophil respiratory burst is decreased in scleroderma and normalized by near-infrared mediated hyperthermia.
Scleroderma Patients Tolerated LED Light With Early Signs of Benefit
Across 14 ulcers on the fingers in 8 patients, a 2019 clinical trial tested low-level light therapy for systemic sclerosis. A custom-built device combining 850, 660, and 405 nm LEDs delivered 46 light exposures at 10 J/cm² and 8.2, 9.1, and 10.4 mW/cm², in sessions of 17.8 and 19.6 minutes, 6 times a week for 21 days, without touching the skin. Blood flow to the ulcers appeared to increase after treatment, and both patient and clinician ratings of the condition improved by a statistically significant margin. Patients tolerated the treatment well and reported a low mean pain rating of 1.6, with no safety concerns arising, though the authors described the sign of benefit as early and tentative.
- Study Type
- Clinical Trial
- Participants
- 8
- Treated Area
- Hands
- Wavelength(s)
- 405, 660, 850 nm
- Distance
- Non Contact
- Session Duration
- 17.8 minutes, 19.6 minutes
- Session Frequency
- 6 per week
- Therapy Duration
- 21 days
- Study Scope
- Systemic Sclerosis
Study Title: A feasibility study of a novel low-level light therapy for digital ulcers in systemic sclerosis.
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 21, 2026