Macena R.L. et al. - Photobiomodulation Combined with Exercise in Fibromyalgia: A Systematic Review and Meta-Analysis

In this systematic review with meta-analysis, the addition of photobiomodulation to an exercise program did not statistically significantly improve pain, functional capacity, depressive symptoms, or quality of life in people with fibromyalgia. The authors rate the certainty of the evidence as very low and conclude that the current data do not allow for either confirming or ruling out a clinically relevant additional effect.

What this study measured

Fibromyalgia is characterized by persistent widespread pain, fatigue, sleep disturbances, and functional impairment. Appropriate physical exercise is one of the best-documented treatment approaches. The question posed here is more specific: Does adding photobiomodulation sessions to this exercise program provide an additional benefit compared to exercise alone?

The authors searched PubMed, the Cochrane Library, PEDro, Scopus, Web of Science, Embase, and LILACS, as well as gray literature via Google Scholar, Open Grey, and ProQuest. The risk of bias in the selected trials was assessed using the Cochrane RoB 2 tool, and the overall certainty of the evidence was assessed using the GRADE method. Five categories of outcomes were analyzed: pressure pain threshold, pain intensity, functional capacity, depressive symptoms, and quality of life.

Key Findings

None of the criteria analyzed reached the threshold for statistical significance. The confidence intervals consistently cross the zero value, and heterogeneity among trials is often very high.

• Pressure pain threshold: mean difference -0.36 (95% CI -1.50 to 0.79; p = 0.54; I² = 80%).
• Pain intensity: mean difference 1.07 (95% CI -1.02 to 3.16; p = 0.32; I² = 95%).
• Objective functional capacity on the Timed Up and Go test: mean difference 0.26 (95% CI -0.13 to 0.65; p = 0.20).
• 6-minute walk test: mean difference -81.92 (95% CI -236.21 to 72.37; p = 0.30; I² = 93%).
• Subjective functional capacity as measured by the FIQ: standardized mean difference of 0.41 (95% CI -1.36 to 2.18; p = 0.65; I² = 0%).
• Depressive symptoms measured by the BDI: mean difference 1.06 (95% CI -6.29 to 8.42; p = 0.78; I² = 53%).
• Quality of life as measured by the SF-36: mean difference 6.29 (95% CI -8.40 to 20.98; p = 0.40; I² = 86%).

The certainty of the evidence is classified as very low according to GRADE, which means that the actual effect is likely to differ substantially from the estimate obtained.

How photobiomodulation works for this indication

Photobiomodulation uses red and near-infrared wavelengths that are absorbed by the mitochondria. The mechanisms described in the literature link this absorption to a modulation of oxidative stress and local inflammatory signaling. In fibromyalgia, the working hypothesis is twofold: to target the peripheral muscular component activated by exercise, and to address the central sensitization phenomena that characterize the syndrome.

This review does not test these mechanisms. It merely measures the clinical outcome observed when the two interventions are combined, and this outcome does not suggest a detectable additional benefit based on the available data.

Limits You Should Know

The authors themselves highlight several limitations. There is considerable heterogeneity across most criteria—up to 95% for pain intensity—which means the trials are difficult to compare with one another. Sample sizes are small, and there are numerous methodological limitations. The very low GRADE certainty means that these results should be interpreted as a lack of evidence of an effect, rather than as evidence of the absence of an effect.

The abstract does not specify either the number of trials included or the irradiation parameters used. However, dose, wavelength, and the timing of application relative to the exercise session are critical variables in photobiomodulation. It is possible that poorly calibrated protocols in the primary trials may explain some of these neutral results.

What This Means in Practice

This review calls for caution. Based on the current evidence, it does not support the idea that adding photobiomodulation to an exercise program improves pain or function in fibromyalgia. Appropriate exercise remains an important part of treatment, and photobiomodulation is not a substitute for any prescribed treatment or follow-up care.

For those affected, the important takeaway is that, to date, there is no documented evidence of additional benefit in this specific scenario. Any decision should be made in consultation with a healthcare professional, taking into account individual tolerance and the overall treatment plan.

Frequently Asked Questions

Does photobiomodulation provide relief from fibromyalgia?

In this review, when combined with exercise, it did not result in a statistically significant improvement in pain. Other studies focusing on photobiomodulation alone have reported different results, fueling an ongoing debate.

Why are these results negative when other studies show positive results?

The heterogeneity of the protocols, the small sample sizes, and methodological differences between trials account for a large portion of these discrepancies. The certainty of the evidence remains very low.

Should you stop exercising if you have fibromyalgia?

No. This review compares exercise combined with photobiomodulation to exercise alone. It does not call into question the benefits of adapted physical activity.

Reference

Macena RL, Barbosa VT, Bertoncello D, Buzanello MR, Bertolini GRF. Efficacy of photobiomodulation combined with exercise in patients with fibromyalgia: A systematic review and meta-analysis. British Journal of Pain, 2026. PMID 42643493. Read on PubMed

This summary is provided for informational purposes only and does not constitute medical advice. Photobiomodulation is not a substitute for prescribed treatment. Consult a healthcare professional.