About the research on this page. The studies cited here investigate photobiomodulation (PBM) as a therapeutic modality and the specific wavelengths used in PBM research — not Mito Red Light devices. The wavelengths in our panels were chosen because the peer-reviewed PBM literature supports them. Evidence levels and study counts reflect the broader research base, not studies of our products. See the full methodology note at the bottom of this page.

Red Light Therapy Safety, Parameters & Wavelengths: Clinical Evidence & Research

560 StudiesPhotobiomodulation (PBM) Source-linked

What the research shows

Our evidence rating: Reassuring safety record in trials; parameter evidence is low certaintyUpdated Reviewed by Alexis Cowan, PhD

Across the trials reviewed on these pages, side effects of light therapy are generally mild. A 2023 systematic review found no clinical trial data linking light therapy for skin rejuvenation to significant adverse events, including new or recurrent cancer (Glass 2023), and a 2026 review of 105 high-intensity laser studies reported no serious adverse events (Penberthy 2026). A 2025 international expert consensus concluded that photobiomodulation is safe for adults and that red light does not cause DNA damage (Maghfour 2025). Light aimed directly into the eyes is different: in children using repeated low-level red light devices for myopia, cone density near the center of the retina was lower than in controls (Liao 2025), and a 2026 meta-analysis of 28 trials found mild, short-lived side effects but called for long-term retinal safety studies (Lin 2026). Do not look into the light, and use eye protection.

Dose and wavelength matter, but the best settings depend on the condition. In a meta-analysis of 96 pain studies, the total energy delivered was the parameter most strongly linked to pain relief (Kate 2018). For knee osteoarthritis, a network meta-analysis ranked 904 to 905 nm as the most effective wavelength for pain, with low-certainty evidence (Fan 2024). Higher-power lasers at 1064 nm showed pain and function benefits in a 2021 review (Penberthy 2021). Most of this research used clinical lasers or LED devices with specific doses, so results cannot be assumed to apply to every device.

Based on 560 indexed studies in this category, 65 of them in people. These studies test photobiomodulation in general, not Mito Red Light devices.

Key studies: Safety, Parameters & Wavelengths

The strongest human evidence: systematic reviews and meta-analyses first, then the newest randomized trials. Each card comes straight from our study database and links to the paper.

Review

Evidence-based consensus on the clinical application of photobiomodulation

et al., J Am Acad Dermatol, 2025. PMID 40253006

Key finding (checked against the abstract)International expert consensus (21 panelists, systematic review plus Delphi). Photobiomodulation is a safe treatment for adults, and red light does not induce DNA damage.
Population
Human (adults): expert consensus informed by a systematic review
Human study

Cone Density Changes After Repeated Low-Level Red Light Treatment in Children With Myopia

et al., JAMA Ophthalmol, 2025. PMID 40272813

Key finding (checked against the abstract)Retrospective cohort, 99 children with myopia. Children using repeated low-level red light devices aimed into the eye had lower cone density within 0.5 mm of the foveal center than controls; image evaluators were masked.
Population
Human (pediatric): 99 patients; retrospective study
Wavelength
650nm
Meta-analysis

Duration-Dependent Efficacy and Clinical Safety of Repeated Low-Level Red-Light Therapy for Paediatric Myopia: A Systematic Review and Meta-Analysis

et al., Clin Exp Ophthalmol, 2026. PMID 41846466

Key finding (checked against the abstract)28 randomized trials, 3,573 children. Repeated low-level red light slowed myopia progression; reported side effects were mild and short-lived. Authors call for longer trials with full retinal safety checks.
Population
Human (pediatric): 28 RCTs, 3,573 children
Systematic review

Photobiomodulation: A Systematic Review of the Oncologic Safety of Low-Level Light Therapy for Aesthetic Skin Rejuvenation

et al., Aesthet Surg J, 2023. PMID 36722207

Key finding (checked against the abstract)Systematic review of clinical and laboratory data. No clinical trial data link light therapy for skin rejuvenation with significant adverse events, including new or recurrent cancer.
Meta-analysis

Utilization of the 1064 nm Wavelength in Photobiomodulation: A Systematic Review and Meta-Analysis

et al., J Lasers Med Sci, 2021. PMID 35155171

Key finding (checked against the abstract)Systematic review of 1064 nm high-power laser. Pain reduced in 90% of study assessments; largest effects in knee arthritis; functional measures improved.
Meta-analysis

Optimal Laser Phototherapy Parameters for Pain Relief.

et al., Photomed Laser Surg, 2018. PMID 29583080

Key finding (checked against the abstract)96 studies, 232 effect sizes. Large average pain relief (d = 1.36). Total energy was the parameter most strongly related to pain relief.
Meta-analysis

A systematic review and network meta-analysis on the optimal wavelength of low-level light therapy (LLLT) in treating knee osteoarthritis symptoms

et al., Aging Clin Exp Res, 2024. PMID 39367994

Key finding (checked against the abstract)Network meta-analysis, 13 studies, 673 participants with knee osteoarthritis. Light beat sham for pain, not function or stiffness; 904-905 nm ranked highest. Low certainty.
Meta-analysis

The importance of power in photobiomodulation: a systematic review and meta-analysis of high-intensity laser therapy.

et al., Front Integr Neurosci, 2026. PMID 42819314

Key finding (checked against the abstract)105 high-intensity laser studies (5,635 participants). No serious adverse events; large, lasting pain reductions in knee, spine and shoulder conditions.
Population
Mixed

Latest human studies: Safety, Parameters & Wavelengths

The 25 most recent human studies in our database for this category.

YearStudyDesignPopulation
2026 Subretinal Fluid After Repeated Low-Level Red Light Therapy Case report Human: Case report
2026 The Effects of Subacute Sunlight Exposure on Skin Thickness: A Pilot Sonographic Study Human study Human
2026 Safety analysis of repeated low-level red light therapy on cone mosaic and microvasculature by adaptive optics scanning laser ophthalmoscopy Human study Human: 8 months
2026 Oral riboflavin supplementation and sunlight exposure: A possible novel and accessible approach to stabilize progressive keratoconus Human study Human
2026 Ambient green light reduces knee pain in osteoarthritis patients Human study Human
2026 The effect of far infrared radiation on maturation in arteriovenous fistulas in patients on hemodialysis: A randomized controlled, multicenter trial RCT Mixed
2025 Green Light and Transcranial Direct Current Stimulation in Migraine Patients: A Preliminary Randomized Control Trial Human study Human
2025 Light transmission and thermal impact of different photobiomodulation therapy devices on the Achilles tendon of human volunteers: A comparative study Human study Mixed
2025 Far infrared therapy improves vascular function by enhancing endothelial function and decreasing arterial stiffness via cytoprotective pathways Human study, n = 50 Human: 50 participants; non-randomized study, controlled
2025 Photosensitivity Episodes Related to Skin Color in People Treated With Dual-Wavelength Low Power Laser Therapy: A Retrospective Cohort Study Human study Human: retrospective study
2025 Rapid, Safe, and Tolerable Healing of Pediatric Skin Injuries with Blue Light Therapy: An Observational Case Series Case series, n = 12 Human: 12 patients; case series
2025 Poor neurological outcome after treatment with photobiomodulation in a patient recovering from sequelae of vertebral artery dissection Human study Human: case report
2025 Dose-dependent tolerability and safety of transcranial photobiomodulation: a randomized controlled trial RCT Human: (secondary analysis)
2025 Effects of repeated use of post-exercise infrared sauna on neuromuscular performance and muscle hypertrophy Human study, n = 40 Human: 40 participants; non-randomized study, controlled
2025 Effect of Repeated Low-Dose UVR Exposure on Skin Inflammation Threshold, Skin Biomarkers, and Vitamin D in Healthy Adults Human study Human
2025 Photobiomodulation (100 mW) caution applied to tattooed skin: a cross-sectional study Human study, n = 30 Human: 30 participants
2025 Flexible, surface-lighting MicroLED skin patch for multiple human skincare Human study Human
2024 Transcranial low-level laser stimulation in the near-infrared-II region (1064 nm) for brain safety in healthy humans Human study Human
2024 Full operating parameter recording as an essential component of the reproducibility of laser-tissue interaction and treatments. RCT Human
2024 Does the skin phototype influence the sensory perception of individuals during photobiomodulation irradiation? Human study, n = 46 Human: 46 participants; (Research letter)
2024 Influence of ultraviolet A1 exposures on mood states: a randomized controlled study RCT Human
2023 Vitamin D Supplementation and Sun Exposure Maintain Blood Pressures of Pregnant Women and Increase Birth Weight in a Randomized Controlled Trial RCT, n = 108 Human: Randomized trial (108 participants)
2023 Clinical wIRA-hyperthermia: heating properties and effectiveness in lower trunk regions and its accordance with ESHO quality criteria for superficial hyperthermia Human study Human
2023 Retinal Damage After Repeated Low-level Red-Light Laser Exposure Human study Human: case report
2022 Improved Oxygenation of Human Skin, Subcutis and Superficial Cancers Upon Mild Hyperthermia Delivered by WIRA-Irradiation Human study Human

What the evidence does not show

  • One best wavelength or dose for every use: optimal settings varied by condition (Kate 2018, PMID 29583080; Fan 2024, PMID 39367994).
  • Long-term safety data for every device type: most evidence comes from clinical lasers and LEDs studied at specific doses.
  • High-certainty evidence for parameter choices: the knee osteoarthritis wavelength ranking was low certainty (Fan 2024, PMID 39367994).

Frequently asked questions

Is red light therapy safe for your eyes?

Avoid looking into the light and use eye protection. Devices that shine red light directly into children's eyes for myopia were linked to lower cone density in the central retina (Liao 2025), and reviewers have called for long-term retinal safety data (Lin 2026).

Is red light therapy safe?

In clinical trials, side effects are generally mild. A 2023 systematic review found no clinical evidence linking light therapy for skin rejuvenation to cancer (Glass 2023), and 105 high-intensity laser studies reported no serious adverse events (Penberthy 2026). A 2025 expert consensus concluded it is safe for adults (Maghfour 2025).

Which wavelength is best?

It depends on the condition. For knee osteoarthritis pain, 904 to 905 nm ranked highest in one network meta-analysis (Fan 2024). For pain overall, total energy mattered more than any other setting (Kate 2018).

Does more power mean better results?

A 2026 review of high-intensity laser found large, lasting pain reductions (Penberthy 2026), but most of the evidence on these pages comes from lower-power devices, and settings must match the condition studied.

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Browse All Safety, Parameters & Wavelengths Studies

All 560 studies in this category from our study database, built on the PBM Research Database by Vladimir Heiskanen.

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Methodology & important context

The published research indexed and referenced on this page studies photobiomodulation (PBM) as a therapeutic modality and the specific wavelengths used in those studies — not Mito Red Light devices specifically. The wavelengths used across our panels were chosen because the peer-reviewed PBM literature supports them: this is where published evidence is deepest, where dosing parameters have been characterized in human studies, and where clinical guidelines (such as WALT for inflammation and pain) exist. Mito Red Light has not funded or conducted registered clinical trials on our specific devices, and the study counts referenced here reflect the broader PBM research base — not studies of our products.

Where review authors graded certainty (for example with GRADE), we report their grade; other ratings are Mito’s summary. Study counts reflect peer-reviewed photobiomodulation research drawn from major scientific literature databases, peer-reviewed journals, and other published research repositories. PBM response varies meaningfully by person, tissue, condition, dose, wavelength, and session timing; outcomes reported in the published literature may not be replicable for every user. Mito Red Light devices are not intended to diagnose, treat, cure, or prevent any disease. If you have a medical condition or are under a physician’s care, please consult your healthcare provider before beginning any photobiomodulation regimen.