Photobiomodulation safety for fibromyalgia patients matters more than it would for most conditions, because fibromyalgia patients are often the ones who cannot tolerate the medications prescribed for their pain. Sedation, weight gain, cognitive dulling, nausea. These side effects drive many to abandon treatment entirely, leaving them managing a multi-symptom condition with no reliable pharmacological option. The safety evidence for photobiomodulation (also known as red and infrared light therapy) is clear: the 2025 systematic review (Martín Pérez et al.), covering 17 studies and 857 participants, reported no serious adverse events attributed to the therapy. The 2026 Ferreira systematic review of photobiomodulation for chronic pain reinforced this finding. Across the entire published trial literature, no serious adverse events have been reported.
This article is part of our complete guide to Red and Infrared Light Therapy for Fibromyalgia.
Key Takeaways
- No serious adverse events across the evidence base: The 2025 systematic review of 17 studies (857 participants) and the 2026 Ferreira chronic pain review both reported no serious adverse events from photobiomodulation. The largest individual trial (160 patients) and the Ribeiro trial (90 patients, blinding of patients, therapists, and assessors) reported no treatment-related adverse events.
- Safety confirmed across delivery methods: Both localized and whole-body photobiomodulation have demonstrated clean safety profiles. The whole-body trials, which deliver near-infrared light to the entire body surface, reported no adverse events across multiple studies with follow-up periods extending to six months.
- No systemic side effects versus substantial medication side effects: The FDA-approved fibromyalgia medications cause sedation, weight gain, dizziness, nausea, and cognitive dulling at rates that drive treatment discontinuation. Photobiomodulation has no reported systemic side effects: no sedation, no weight gain, no cognitive impairment, and no withdrawal effects upon stopping treatment. A 2024 overview of Cochrane Reviews found only about 1 in 10 patients achieves substantial pain relief from these medications.
Why Safety Matters More for Fibromyalgia Patients
The context for evaluating photobiomodulation safety is the side effect profile of the drugs currently prescribed for fibromyalgia. The three FDA-approved medications (pregabalin, duloxetine, and milnacipran) cause side effects that are frequently intolerable for this patient population.
The 2024 overview of Cochrane Reviews (Moore et al.) documented that only approximately 1 in 10 fibromyalgia patients achieves substantial pain relief from these drugs, and the side effects cause many patients to discontinue treatment. Fibromyalgia patients are already dealing with fatigue, sleep disruption, and cognitive difficulties. Medications that worsen these symptoms create a genuine clinical paradox: the treatment amplifies the condition it is prescribed to manage.
Photobiomodulation has no reported systemic side effects across the entire published trial literature: no sedation, weight gain, cognitive impairment, nausea, or withdrawal effects upon cessation. For a patient population that has often exhausted pharmacological options due to intolerance, this safety profile is the defining clinical advantage.
Dr. Carter, who reviewed the evidence for this article, puts the safety data in clinical context:
Fibromyalgia patients are often chemically sensitive. They react to medications that other populations tolerate. So when you look at the photobiomodulation evidence base, 17 studies, 857 participants, no serious adverse events, that safety profile is not just a nice addition. For fibromyalgia patients specifically, it is a defining clinical advantage. Many of these patients have cycled through multiple medications and abandoned them due to side effects. A therapy with genuine efficacy and this tolerability profile fills a gap that is concrete and documented.— Dr. William Carter, MD
Safety Across Individual Trials
No treatment-related adverse events were reported in the largest photobiomodulation trial in fibromyalgia. The Silva et al. (2018) study enrolled 160 patients and delivered multi-wavelength photobiomodulation (905nm super-pulsed laser, 640nm red LEDs, 875nm infrared LEDs) to 11 tender point locations twice weekly for 10 weeks. Clean safety record throughout.
The Ribeiro et al. (2023) trial randomized 90 patients to photobiomodulation combined with static magnetic field or placebo. The trial blinded patients, therapists, and assessors. No adverse events were reported.
The whole-body photobiomodulation research from the University of Granada tracked the same patient cohort across two studies. The Navarro-Ledesma et al. short-term trial (2022) found no adverse events, and the 6-month follow-up (2024) confirmed this through extended observation. Six months of follow-up with nothing flagged.
Smaller trials confirmed the pattern. Ruaro et al. (2014), using 670nm laser for fibromyalgia, and Fitzmaurice et al. (2023), running a whole-body feasibility trial at the University of Birmingham with 24-week follow-up, both reported no adverse effects.
Across the fibromyalgia photobiomodulation evidence base, no published trial has attributed a serious adverse event to the therapy.
What the Review Literature Concludes
The review-level evidence is consistent. The 2019 Yeh meta-analysis explicitly concluded that photobiomodulation is safe and well-tolerated for fibromyalgia. The 2025 Martín Pérez systematic review confirmed that finding across a broader base of 17 studies. And the 2026 Ferreira systematic review extended the assessment to chronic pain broadly, noting low adverse event incidence across all included trials, fibromyalgia studies included, and stating that this reinforces the therapy's safety profile.
Broader reviews of photobiomodulation for pain and musculoskeletal conditions reach the same conclusion. The González-Muñoz et al. (2023) review in Healthcare found that the therapy positively influenced chronic pain outcomes across the included RCTs. De Oliveira et al. (2022), writing in the European Journal of Physical and Rehabilitation Medicine, described photobiomodulation as a non-invasive, safe, drug-free, and side-effect-free method for pain relief in musculoskeletal conditions including fibromyalgia. (For the full clinical evidence, see PBM for Fibromyalgia: Clinical Evidence.)
Conclusion
Photobiomodulation's safety profile across fibromyalgia trials is consistent and clean: no serious adverse events across 17 studies and 857 participants, confirmed by both fibromyalgia-specific and broader chronic pain reviews. For a patient population where medication side effects are often as debilitating as the condition itself, a therapy with documented efficacy and this tolerability record addresses a real gap in fibromyalgia management. The safety data applies to the wavelengths and protocols studied in clinical trials. Patients considering treatment should confirm their device parameters fall within the studied ranges and discuss photobiomodulation with their healthcare provider. The evidence base gives them a clear foundation for that conversation.
