An interventional study of Green Light in Fibromyalgia, sponsored by University of Arizona. Not yet recruiting at 1 site in United States. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-04-03.
Sponsored by University of Arizona · Not applicable, Interventional, and Treatment
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.
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.
After a patient is consented, investigators will collect the baseline Fibromyalgia Impact Questionnaire survey (FIQ), thermal and mechanical pain detection and tolerance threshold, conditioned pain modulation (CPM), collect cerebrospinal fluid (CSF), and obtain positron emission tomography scan (PET scan) for microglia baseline activity. It is expected that the PET scan will take place on different day given the time needed and preparation for the completion of a PET scan. Investigators expect the baseline value collections to take 1-2 days to complete. Once all baseline values are obtained, the light therapy exposure will begin. The start of light exposure will be considered the start of Week 1. Investigators will follow up with the patient over the phone every 2 weeks +/- 1 week to ensure safety and compliance and to answer any questions the patient may have. Recruited patients will also have investigator's contact information to contact investigators with any urgent questions. At the end of Week 10, investigators will obtain the final values for the FIQ survey, thermal and mechanical pain detection and tolerance threshold, CPM, collect CSF, and obtain PET scan.
1,336 studies on the registry are indexed under Fibromyalgia; 266 are open to participants now.
This study's planned enrollment of 70 is above the median of 60 across 1,035 interventional studies indexed under Fibromyalgia.
Browse Fibromyalgia studies →University of Arizona is the lead sponsor of 466 studies on the registry; 87 are open to participants now.
Of its 47 completed or terminated interventional studies of FDA-regulated products, 29 (62%) have results posted.
Counted across the registry records on this site, refreshed daily.
Exclusion Criteria:
Subjects randomized to this arm will be exposed to GLED 2 hours a day for 10 weeks
Device: Green Light
Subjects randomized to this arm will be exposed to WLED 2 hours a day for 10 weeks
Device: Green Light
This is a low-energy device. It produces almost no heat because it uses an LED source for light. The device does not store energy or electrical power that can be discharged later.
Decreased activation of glial cells.
By exposure to GLED investigators hypothesize that glial cells will be decreased, investigators will measure this by using positron emission tomography (PET) scan, scans will be conducted at baseline and the end of study
Time frame: [Time Frame: 10 - 22 weeks, depending on study arm]
Decreasing Central Nervous System inflammation (CNS), Increasing Endorphins.
By exposure to GLED, investigators hypothesize that inflammation in the CSF will be decreased and increased endorphin levels, this will be demonstrated by measuring cerebrospinal fluid (CSF) cytokines at baseline and at the end of study.
Time frame: [Time Frame: 10 - 22 weeks, depending on study arm]
Decreasing the activity of ascending pain pathway, and increasing the activity the descending pain pathway
Decreasing the activity of the ascending pain pathway shown by decreased pain scores from repeated noxious stimulation (temporal summation) as compared to baseline, increasing the activity of the descending pain pathway measured by increasing the pain threshold to noxious stimulation while patients submerge their hand in an ice water bath as compared to baseline.
Time frame: [Time Frame: 10 - 22 weeks, depending on study arm]
Improvement in Fibromyalgia Impact Questionnaire score
These will be completed at baseline and at the end of study. A survey to evaluate the effects of Fibromyalgia. The scale ranges from 0-100. 0 means no impact. 100 means there is a severe negative impact secondary to fibromyalgia. The scale is subjective in nature.
Time frame: [Time Frame: 10 - 22 weeks, depending on study arm]
Decreased objective and subjective pain scores to mechanical and thermal stimulation
Investigators will compare pain scores at baseline to end of study. The scale ranges from 0-100%. This is a reported value by the patient which is subjective in nature.
Time frame: [Time Frame: 10 - 22 weeks, depending on study arm]
Plan to share: No
This study is not yet recruiting, as verified in Mar 2026. You cannot join it, but the record below documents what was studied.
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University of Arizona