Green light therapy and how it may ease fibromyalgia pain
Tests green light exposure to learn how it affects pain in fibromyalgia.
Key facts
- Who runs it
- University of Arizona
- Where
- Tucson, United StatesSee the site
- Trial code
- Registry title
- Elucidating the Central Mechanisms of Action for Green Light Therapy in Managing Chronic Pain
- Status
- Not yet recruiting
- People taking part
- 70 people, planned
- Starts
- 1 Dec 2026
- Expected to end
- 30 Dec 2029
- Type of study
- Interventional, 2 groupsOne group gets a placebo (a dummy treatment), for comparison.
- Treatments tested
- Green Light
- Record updated
- 3 April 2026
Who can take part
AI summary
From the trial's eligibility criteria. Machine-read from the registry text on this page, so it can be wrong. The registry text below and the trial team decide who can take part.
The trial is looking for adults with fibromyalgia whose pain is not controlled by medical treatment. It tests green light therapy against white light.
- Age
- 18 years or older
- Sex
- All sexes can join
- Disease stage
- Fibromyalgia by the 2016 revisions to the 2010/2011 diagnostic criteria. Average pain score of 5 out of 10 or more over the 10 weeks before joining.
- Earlier treatment
- Medical therapy must have failed to control the pain.
- Biomarker or test result
- People with a TSPO gene type that binds weakly (low affinity binders) cannot join, because the PET scan tracer may not work well.
Main reasons for not taking part
- Serious mental illness with loss of contact with reality, such as delusions or hallucinations
- History of color blindness or cataracts that are not corrected
- Receiving payment for their medical condition
- Low affinity binder genotype for TSPO
- Cannot speak and understand English
The registry criteria, word for word
Show all 7 criteriaShow less
Who can take part
- 18 years or older who can speak and understand English
- Meets the diagnostic criteria for fibromyalgia accroding to the 2016 revisions to the 2010/2011 fibromyalgia diagnostic criteria
- Average numeric pain score of 5 out of 10 or greater over the 10 weeks prior to enrolling in the study, and failure of medical therapy to control their pain
Who cannot take part
- Serious mental illness defined as distortions of perception, delusions, hallucinations, and unusual behaviors resulting in loss of contact with reality. This will be assessed during the screening interview. Patients with psychiatric disorders will have their medical record reviewed prior to enrollment
- Subjects receiving remuneration for their medical condition
- History of color blindness or uncorrected cataracts
- Genotype of low affinity binders for translocator protein, (TSPO), as patients with low affinity binding TSPO may not have adequate uptake for the radioactive tracer used for the PET scan
Where in United States
- Banner University Medical Center Multispecialty Services ClinicTucson, United StatesContact: Mohab M Ibrahim, PhD., MDNot yet recruiting
About the trial
What the trial wants to find out
Investigators have previously shown that specific colors of light can alter nociception. Green light emitting diode exposure (GLED) provides long-lasting antinociception in rodents, through the visual system. No adverse effects were noted, and motor performance was not impaired. Investigator clinical trials have shown GLED is also effective in decreasing pain intensity of fibromyalgia patients and decreasing the number of headache-days per month in migraine patients. However, investigators do not yet understand the mechanisms by which GLED reduces pain.
Read full original descriptionShow less
Understanding the mechanisms of action of GLED will provide additional support for using light therapy as both a treatment and as a possible diagnostic tool. While investigators do not fully understand the mechanisms of action of GLED, investigators do know that it is centrally mediated.
To better elucidate the mechanism of action for GLED, investigators propose a single-blinded randomized placebo-controlled clinical trial to elucidate the central mechanism(s) of action that GLED therapy has in improving fibromyalgia pain, conducted by a team with a successful record of collaboration. Investigator's hypothesis is that GLED decreases neuroinflammation leading to modulation of the signaling in the ascending and descending pain pathways.
The 2 groups in the trial
- Green light-emitting diode (GLED)Treatment being tested
Subjects randomized to this arm will be exposed to GLED 2 hours a day for 10 weeks
Treatment: Green Light
- White light-emitting diode (WLED)Placebo, for comparison
Subjects randomized to this arm will be exposed to WLED 2 hours a day for 10 weeks
Treatment: Green Light
Questions to ask the study team
- How often do I need to come in, and for how long each time?
- Are travel costs paid?
- Can I keep my own doctor?
- What happens if I want to stop?
Contact the study team: see the registry record → Contacts and Locations
Print a page for my doctorData and sources
- Registry record
- Listed on ClinicalTrials.gov.
- Official title
- Elucidating the Central Mechanism(s) of Action for Green Light Therapy in Managing Chronic Pain
- Plain-language title
- Green light therapy and how it may ease fibromyalgia painGenerated from the registry record. The registry title is the official one.
- AI summary
- From the trial's eligibility criteria. Read by machine on 14 November 2026.
- Record updated
- 3 April 2026