Recruiting

Chromatic Light

Sponsor:

University of North Carolina, Chapel Hill

Code:

NCT07825792

Conditions

Fibromyalgia

Musculoskeletal Pain

Eligibility Criteria

Sex: All

Age: 18+

Healthy Volunteers: Not accepted

Interventions

S-Cone Stimulating Chromatic Light

Equal-Energy White Light

Study Details

Brief summary:

This pilot randomized, double-blind, crossover clinical trial will evaluate the feasibility and preliminary efficacy of chromatic (colored) light exposure for reducing pain severity and pain sensitivity in adults with fibromyalgia or chronic widespread pain and fatigue. Participants will complete daily symptom surveys throughout the study and undergo patient-reported outcome assessments and quantitative sensory testing at multiple timepoints.

Participants will be randomized to receive either S-cone stimulating chromatic light or equal-energy white light for 2 hours daily over a 7-day treatment period. Following a 1-week washout, participants will cross over to the alternate condition. Outcomes will examine feasibility, changes in pain severity, pain interference, and measures of pain sensitivity. Total study duration is approximately 35 days.

Conditions

Fibromyalgia

Musculoskeletal Pain

Study ID

NCT07825792

Start date

Nov 9, 2026

Status verified date

Sep, 2026

Completion date

Jan 1, 2028

Anticipated

Primary completion date

Jan 1, 2028

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: All

Age: 18+

Healthy Volunteers: Not accepted

Inclusion Criteria:

  • Adults ≥ 18 years of age.
  • Individuals who have been diagnosed with fibromyalgia or suffer from chronic widespread pain and fatigue.
  • An average pain severity ≥4 on the 0-10 NRS over the month prior to enrollment.
  • Pain symptoms present for 3 months or longer.
  • Pain must be present in 4 out of 5 body regions.
  • A score of ≥7 on the Widespread pain index (WPI) and ≥5 on the symptom severity scale (SSS), or 4-6 on the WPI and ≥9 on the SSS in the 2016 Fibromyalgia Questionnaire.
  • Willingness to adjust light levels in home environment so that the illumination (measured in lux) provided by the light bulbs is twice the ambient room illumination (also measured in lux).
  • Willingness to use study lightbulbs for 2 consecutive hours a day for 7 consecutive days according to study specifications for both conditions (total of 14 days using lightbulbs)
  • Alert and oriented, and able to provide informed consent
  • Ability to read and speak English to complete validated questionnaires.

Exclusion Criteria:

  • Vision disorders or conditions resulting in severe vision impairment or blindness
  • Individuals with self-report of color blindness, uveitis or cataracts.
  • Prisoner Status
  • Pregnancy
  • History of photosensitivity or sensitivity to scintillating (mildly flickering) light.
  • History of seizure disorder.
  • Individuals living in households with people who have a history of seizure disorders.
  • Analgesic treatment plan changes anticipated in the next 3 months (surgery, analgesic medication changes, injections, pain procedures, etc.).
  • Other history or condition that would, in the investigator's judgment, indicate that the individual would highly likely be non-compliant with the study or unsuitable for the study

Study Design

Enrollment

40 participants

Anticipated

Allocation

Randomized

Intervention Model

Crossover

Primary purpose

Treatment

Interventions and Outcome Measures

Arms

experimental: S-cone stimulating chromatic light first followed by equal-energy white light

Participants randomized to this sequence will receive S-cone stimulating chromatic light during the first treatment period, followed by equal-energy white (flickering along the L/M axis) light during the second treatment period. Each treatment period consists of 2 hours of daily light exposure for 7 consecutive days, ideally between 5:00 a.m. and 10:00 a.m., delivered using programmed "TUO" light bulbs. The two treatment periods are separated by a 1-week washout period. Participants complete daily symptom surveys, patient-reported outcome measures, and quantitative sensory testing throughout the study.

experimental: Equal-energy white light first followed by S-cone stimulating chromatic light

Participants randomized to this sequence will receive equal-energy white light (flickering along the L/M axis) during the first treatment period, followed by S-cone stimulating chromatic light during the second treatment period. Each treatment period consists of 2 hours of daily light exposure for 7 consecutive days, ideally between 5:00 a.m. and 10:00 a.m., delivered using programmed "TUO" light bulbs. The two treatment periods are separated by a 1-week washout period. Participants complete daily symptom surveys, patient-reported outcome measures, and quantitative sensory testing throughout the study.

Interventions

S-Cone Stimulating Chromatic Light

Participants receive exposure to S-cone stimulating chromatic light delivered via programmed TUO light bulbs. Light is administered for 2 hours daily for 7 consecutive days, ideally between 5:00 a.m. and 10:00 a.m.. Participants use the light in their home environment while engaging in normal daily activities. Light intensity is maintained at a minimum of twice the ambient room illumination using an illuminometer provided by the study. This intervention is designed to selectively stimulate short-wavelength-sensitive (S-cone) photoreceptors.

Equal-Energy White Light

Participants receive exposure to a light that appears equal-energy white that flickers along the L/M axis delivered via programmed TUO light bulbs. Light is administered for 2 hours daily for 7 consecutive days, ideally between 5:00 a.m. and 10:00 a.m. Participants use the light in their home environment while engaging in normal daily activities. Light intensity is maintained at a minimum of twice the ambient room illumination using an illuminometer provided by the study. This intervention serves as the control condition for comparison with the S-cone stimulating chromatic light intervention.

Primary outcome measure

  • Percentage of participants completing follow-up visits after each intervention period [ Time Frame: Throughout study participation (35 days) ]
  • Percentage of daily flash surveys completed during the two 7-day stimulation periods [ Time Frame: Throughout the two 7-day stimulation periods (14 eligible survey timepoints during active treatment period) ]
  • Percentage of prescribed light stimulation sessions completed based on participant self-report [ Time Frame: Throughout the two 7-day stimulation periods (14 eligible survey timepoints during active treatment period) ]

Central Contacts and Locations

Central contacts

Matthew Mauck, MD, PhD

919-966-5136matt_mauck@med.unc.edu

Locations

University of North Carolina at Chapel Hill

Recruiting

Chapel Hill, North Carolina, United States, 27514

Contacts

Matt Mauck, MD, PhD

919-966-5136matt_mauck@med.unc.edu

More Information

Sponsor

University of North Carolina, Chapel Hill

Last update posted

Nov 2, 2026

Last verified

Sep, 2026

Keywords

  • Fibromyalgia
  • Musculoskeletal Pain
  • Analgesia

Trial information was received from ClinicalTrials.gov and was last updated on 2026-11-03. This information was provided to ClinicalTrials.gov by University of North Carolina, Chapel Hill on 2026-11-02. Recruitment status is synced daily from ClinicalTrials.gov and may not reflect the sponsor's current status. Confirm during your call.