Green Light Therapy for Chronic Pain

Overseen By Laurent F Martin, PhD

Age: 18 - 65

Sex: Any

Trial Phase: Academic

Sponsor: University of Arizona

Disqualifiers: Serious mental illness, Colorblindness, Tissue damage, others

Compensation: Varies

Number of Visits: 2

Duration: 1 day

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial aims to explore how exposure to green light, using a Green Light Emitting Diode, can help relieve pain. Research has already shown that green light can reduce pain, but researchers seek to understand why it works. Participants will be exposed to green or white light to compare effects. The trial seeks healthy men and women without chronic pain and no history of nerve issues in specific areas like the forearms or shoulders. As an unphased trial, this study offers participants the chance to contribute to groundbreaking research on pain relief through green light exposure.

Do I need to stop my current medications for the trial?

The trial information does not specify whether you need to stop taking your current medications.

What prior data suggests that green light exposure is safe for humans?

Research has shown that green light therapy is generally safe. Studies have found that people using green light felt less pain and did not experience significant side effects. For instance, one study discovered that green light exposure greatly reduced the number of headache days, with no major negative effects reported. Another study suggested that green light therapy can effectively reduce chronic pain and might be a safe alternative to medication.

Overall, evidence indicates that green light therapy is well-tolerated. Participants did not face serious safety issues, making it a promising option for those seeking to manage pain without drugs. ^{1 2 3 4 5}

Why are researchers excited about this trial?

Researchers are excited about using green light therapy for chronic pain because it offers a non-invasive, drug-free approach that may reduce pain without the side effects associated with medications like opioids or NSAIDs. Unlike traditional treatments that often rely on pharmaceuticals to manage symptoms, this therapy utilizes a specific wavelength of green light to potentially alter pain perception directly through visual pathways. The method of using a green light-emitting diode is innovative as it targets pain pathways uniquely and could provide relief in a safe, accessible manner without the risks of addiction or adverse reactions.

What evidence suggests that green light exposure is effective for chronic pain?

Studies have shown that exposure to green light can reduce both sudden and long-lasting pain. In one study, participants who spent several hours each day in green light reported less pain and an improved quality of life. Another study found that green light therapy eased pain from conditions such as migraines, low back pain, and fibromyalgia. Although the exact mechanism of green light remains under investigation, early research suggests it might reduce inflammation. In this trial, participants will be exposed to either green light or white light as a comparator. Overall, evidence suggests that green light therapy could be a promising method for managing chronic pain. ^{1 2 3 6 7}

Who Is on the Research Team?

Mohab Ibrahim, PhD, MD.

Principal Investigator

University of Arizona

Are You a Good Fit for This Trial?

This trial is for English-speaking men and women aged 18-50 who are generally healthy, without chronic pain or neuropathies in certain body areas. It's not suitable for those with colorblindness, uncorrected cataracts, serious mental illness, or tissue damage where testing will occur.

Inclusion Criteria

I do not have a history of chronic pain.

I am a healthy adult between 18 and 50 years old.

Able to speak and understand English

Exclusion Criteria

You have trouble seeing colors or have not had surgery for cataracts.

I do not have tissue damage in my forearms, hands, or upper back.

You have severe mental illness that causes you to have trouble telling what's real and what's not.

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

1-2 weeks

Baseline Assessment

Participants undergo baseline testing of pain pathways and brain wave activities using thermal and mechanical stimulations and EEG

1 day

1 visit (in-person)

Treatment

Participants are exposed to green or white light for two hours, followed by post-exposure testing of pain pathways and EEG

1 day

1 visit (in-person)

Follow-up

Participants are monitored for any delayed effects of light exposure on pain perception and brain activity

1-2 weeks

What Are the Treatments Tested in This Trial?

Interventions

• Green Light Emitting Diode

Trial Overview The study aims to understand how green light exposure can relieve pain by comparing the effects of green and white light-emitting diodes (LEDs) on participants. The mechanisms behind the pain-relieving properties observed in previous studies are being investigated.

How Is the Trial Designed?

Group I: Green Light Exposure Active Control 1 Intervention

Subjects will complete thermal and mechanical pain threshold detection tests and Electroencephalography (EEG). After completion, subjects will be exposed to a green light-emitting diode for two hours. After exposure, thermal and mechanical pain threshold assessments and Electroencephalography (EEG) will be conducted.

Group II: White Light Exposure Placebo Group 1 Intervention

Subjects will complete thermal and mechanical pain threshold detection tests and Electroencephalography (EEG). After completion, subjects will be exposed to a white light-emitting diode for two hours. After exposure, thermal and mechanical pain threshold assessments and Electroencephalography (EEG) will be conducted.

Who Is Running the Clinical Trial?

University of Arizona

Lead Sponsor

Trials

545

Recruited

161,000+

Published Research Related to This Trial

Phototherapy, particularly using red light (660 nm), can effectively reduce pain in conditions like neuropathies and complex regional pain syndrome-I, but visual exposure to the same wavelength may worsen migraines.

Green light exposure has been shown to alleviate pain in various conditions, including migraines and fibromyalgia, highlighting the importance of light color and exposure method in pain management.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Mechanisms and Pathways of Pain Photobiomodulation: A Narrative Review. Cheng, K., Martin, LF., Slepian, MJ., et al.[2023]

In a clinical trial involving 43 participants, low-level laser therapy using green and violet wavelengths significantly reduced chronic musculoskeletal pain, with visual analog pain scores dropping from 71.79 to 34.02 just three minutes after treatment (p < 0.0001).

A remarkable 81.4% of participants experienced a reduction of 30% or more in their pain scores, supporting the efficacy of this therapy and leading to the first FDA clearance for the combined use of these laser wavelengths.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Assessing the Impact of High Photon Energy Wavelengths on the Treatment of Chronic Neck and Shoulder Pain. Sammons, T., Gair, K., Silverman, RG., et al.[2023]

Citations

1. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC7861466/

Green Light Exposure Improves Pain and Quality of Life in ... We demonstrated that exposure to green light-emitting diodes (GLED) for 8 hours/day for 5 days resulted in antinociception and reversal of thermal and ...

2. clinicaltrials.gov clinicaltrials.gov/study/NCT03677206

NCT03677206 | The Effect of Light Therapy on Chronic Pain The investigators hypothesis is that participants exposed to green and blue light will have less use of analgesics and will have better life quality. Detailed ...

3. sciencedirect.com sciencedirect.com/science/article/pii/S1526590022004370

Green Light Exposure Elicits Anti-inflammation ... Green light therapy has been shown to be effective in reducing chronic pain in humans and rodents. However, its underlying mechanisms remain incompletely ...

4. annualreports.healthsciences.arizona.edu annualreports.healthsciences.arizona.edu/2023/story/cpac-green-light-therapy/

Shining a green light on pain relief - Annual Reports From 2016 to 2019, 21 people with fibromyalgia who were out of traditional treatment options completed a pilot clinical study to test the effectiveness of green ...

5. journals.lww.com journals.lww.com/pain/fulltext/2025/06000/visual_exposure_to_green_light_therapy_reduces.8.aspx

Visual exposure to green light therapy reduces knee joint... Visual exposure to dim, green, light has been found to reduce pain levels in patients living with migraine, low back pain, and fibromyalgia.

6. pubmed.ncbi.nlm.nih.gov pubmed.ncbi.nlm.nih.gov/32903062/

Evaluation of green light exposure on headache frequency ... Green light emitting diodes resulted in a significant decrease in headache days from 7.9 ± 1.6 to 2.4 ± 1.1 and from 22.3 ± 1.2 to 9.4 ± 1.6 in ...

7. jrd.or.kr jrd.or.kr/journal/view.html?uid=1539&vmd=Full

Effects of light-emitting diode therapy on hand stiffness and ... Results: After undergoing LEDT, participants showed clinically significant improvements in VAS pain scores at weeks 2, 4, and 8 compared to ...