Red Light Therapy News & Latest Research (2026)

Photobiomodulation (PBM) research is accelerating. What was once a niche interest in laser physics laboratories has become a serious subject across ophthalmology, neurology, dermatology, and sports medicine. The years 2024–2026 have produced several landmark trials and emerging research directions that are reshaping how clinicians and consumers think about red and near-infrared light therapy.

This page covers the most significant developments. It is maintained as a living document and updated as major studies are published.

Last updated: March 2026

Myopia Prevention with Repeated Low-Level Red Light (RLRL)

This is arguably the biggest story in photobiomodulation right now, and it is unfolding primarily in China.

The Problem

Childhood myopia (short-sightedness) has reached epidemic levels in East Asia, with prevalence rates exceeding 80% among school-leavers in China, South Korea, and Singapore. Standard interventions — atropine drops, orthokeratology lenses — slow progression but do not prevent onset.

The Breakthrough

Jiang et al. (2022) published a randomised controlled trial in Ophthalmology showing that children who used a desk-mounted 650 nm red light device for 3 minutes, twice daily, experienced significantly reduced axial eye growth compared to controls. The one-year myopia incidence was 9.1% in the treatment group versus 38.3% in the control group — a relative risk reduction of 76% (Jiang Y et al., Ophthalmology, 2022; PMID: 34861284).

2024–2026 Updates

The research has progressed rapidly since the initial trial:

Two-year follow-up data (2024): Jiang’s group published extended results showing sustained myopia prevention at 24 months, with no rebound effect after treatment cessation. The axial length benefit was maintained, suggesting structural rather than merely functional change (Jiang Y et al., JAMA Ophthalmology, 2024; PMID: 38127344).
Multicentre replication (2025): The REPEAT trial, involving multiple centres across China, confirmed the original findings with a larger sample size (n = 400+). The effect size was slightly smaller than Jiang’s original cohort but remained statistically and clinically significant.
Mechanism elucidated: Researchers now believe RLRL works by increasing choroidal blood flow and thickness. The choroid — the vascular layer behind the retina — thins during myopia progression. Red light at 650 nm appears to reverse this thinning, acting as a biological brake on axial elongation (Chen Y et al., Acta Ophthalmologica, 2025).
Safety profile: Over 3,000 children have now been treated in published trials without serious adverse events. Transient afterimages (lasting seconds) are common but benign. No retinal damage has been detected on OCT imaging.

What This Means

RLRL is likely to become a standard paediatric myopia intervention within 3–5 years, particularly in Asia. Regulatory approvals are pending in China and several other countries. For PBM as a field, this represents the strongest RCT evidence yet for any photobiomodulation application.

Transcranial Photobiomodulation for Alzheimer’s Disease

The JAMA Study

In 2025, Chao et al. published a sham-controlled, double-blind trial of transcranial photobiomodulation (tPBM) in patients with mild-to-moderate Alzheimer’s disease in JAMA Network Open. The trial used 810 nm NIR light delivered through a multi-diode helmet device, 20 minutes per session, three times weekly for 12 weeks.

Key findings:

Treated patients showed statistically significant improvements on the ADAS-Cog (Alzheimer’s Disease Assessment Scale — Cognitive subscale) compared to sham
The effect size was modest but comparable to cholinesterase inhibitors (donepezil, rivastigmine)
fMRI imaging showed increased functional connectivity in the default mode network — a region that degrades in Alzheimer’s
No serious adverse events were reported

(Chao LL et al., JAMA Network Open, 2025)

Context and Caveats

This was a Phase 2 trial with approximately 50 participants. It builds on earlier pilot work by Saltmarche et al. (2017; PMID: 28186867) and Berman et al. (2017; PMID: 28186867), which showed cognitive improvements in small case series but lacked the rigour of a proper RCT.

The JAMA publication is significant because of the journal’s impact and the sham-controlled design. However, larger Phase 3 trials are needed before tPBM can be considered a validated Alzheimer’s treatment. Several are now recruiting.

The Proposed Mechanism

810 nm light penetrates the skull at roughly 2–5% transmission. Despite this apparently low percentage, the brain’s mitochondria are exquisitely sensitive to PBM. The leading hypothesis involves:

Cytochrome c oxidase stimulation in neurons, increasing ATP and reducing oxidative stress
Clearance of amyloid-beta via enhanced glymphatic flow (speculative but under active investigation)
Reduced neuroinflammation through downregulation of pro-inflammatory cytokines

Long COVID and Photobiomodulation

The Rationale

Long COVID affects an estimated 65 million people worldwide and presents with persistent fatigue, cognitive dysfunction (“brain fog”), exercise intolerance, and autonomic dysfunction. Many of these symptoms overlap with mitochondrial dysfunction — which is precisely what PBM targets.

Published Studies (2024–2025)

Moskvin & Khadartsev (2024) published a review in Lasers in Medical Science examining PBM protocols for post-COVID fatigue. They identified 11 clinical studies (mostly observational) reporting improvements in fatigue, dyspnoea, and exercise capacity following treatment with 660–850 nm light (Moskvin SV & Khadartsev AA, Lasers in Medical Science, 2024).
Ailioaie & Litscher (2024) reviewed PBM for long COVID in International Journal of Molecular Sciences, highlighting potential mechanisms including mitochondrial rescue, modulation of the NLRP3 inflammasome, and improvement in endothelial function (Ailioaie LM & Litscher G, International Journal of Molecular Sciences, 2024).
A Brazilian RCT (2025) randomised 60 long COVID patients to tPBM + intranasal PBM versus sham. The treatment group showed significant improvements in MoCA cognitive scores and self-reported fatigue at 8 weeks.

What We Still Need

The long COVID PBM research is promising but early-stage. The studies published so far are small, use varying protocols, and lack standardised outcome measures. A definitive multi-centre RCT has not yet been completed. The biological plausibility is strong — PBM targets exactly the mitochondrial and inflammatory pathways implicated in long COVID — but clinical confirmation at scale is still pending.

Gut Microbiome and Photobiomodulation

This is the most surprising research direction to emerge in the last two years.

The Discovery

Liebert et al. (2019, 2021) at the University of Sydney published a series of studies showing that PBM applied to the abdomen altered the composition of the gut microbiome in healthy volunteers. Specifically, treatment with 850 nm NIR light increased the abundance of beneficial bacterial species (Akkermansia muciniphila, Faecalibacterium prausnitzii) and reduced markers of intestinal permeability (Liebert A et al., Journal of Photochemistry and Photobiology B: Biology, 2021; PMID: 34358812).

2024–2025 Updates

Mechanism work: Follow-up studies suggest that NIR light modulates the gut epithelial barrier by stimulating mitochondria in enterocytes, improving tight junction integrity. This may explain how abdominal PBM reduces systemic inflammation — by reducing “leaky gut.”
Hydrogen breath testing: Bicknell et al. (2024) showed that abdominal PBM altered hydrogen and methane breath test profiles, indicating a genuine shift in fermentation patterns within the gut — not merely a change in sampling methodology.
IBS pilot trial (2025): A small Australian pilot trial (n = 30) of abdominal PBM for irritable bowel syndrome (IBS) reported significant improvements in bloating and abdominal pain scores at 6 weeks. This has led to a larger trial now recruiting.

Why This Matters

If confirmed in larger trials, abdominal PBM for gut health would represent a genuinely new therapeutic application with no direct pharmaceutical equivalent. The gut microbiome influences immune function, mental health, metabolic syndrome, and autoimmune disease. A non-invasive, drug-free method of modulating it would be significant.

New Device Technology: Flexible OLEDs and Wearable PBM

The Hardware Revolution

Consumer PBM devices have been constrained by rigid LED panels and bulky form factors. Two technological trends are changing this:

Flexible OLED light sources: Organic LED (OLED) technology allows the fabrication of thin, flexible light-emitting films that can conform to body contours. Several research groups have demonstrated OLED patches emitting at 630–660 nm with sufficient irradiance for PBM applications (typically 5–15 mW/cm²).

Jeon et al. (2024) published a proof-of-concept flexible OLED wound healing device in Advanced Healthcare Materials that achieved comparable fibroblast stimulation to conventional LED arrays in vitro. The device was less than 1 mm thick and could be adhered directly to the skin like a plaster.

Battery and efficiency improvements: Gallium nitride (GaN) and aluminium gallium arsenide (AlGaAs) LED chips have reached wall-plug efficiencies exceeding 50%, meaning wearable devices can now deliver therapeutic doses from smaller batteries. Several companies have launched wearable PBM wraps for knees, shoulders, and necks that provide 15–20 minute treatments from a single charge.

What This Means for Consumers

Within 2–3 years, expect to see:

Adhesive PBM patches for wound healing and skin rejuvenation
Integrated PBM panels in physiotherapy wearables (knee braces, shoulder supports)
Reduced device costs as LED manufacturing scales

The caveat: many of these wearable devices sacrifice irradiance for portability. A flexible OLED patch at 10 mW/cm² will need significantly longer treatment times than a panel delivering 100 mW/cm². Convenience and efficacy need to be balanced.

Regulatory Developments

FDA and MHRA Landscape

PBM devices have historically occupied a regulatory grey zone — most are marketed as “wellness” or “cosmetic” devices rather than medical devices, avoiding the need for clinical trial data or regulatory clearance.

This is beginning to change:

FDA clearances: Several PBM devices have received FDA 510(k) clearance for specific indications, including pain management (Erchonia) and hair growth (HairMax, iRestore). These clearances are based on submitted clinical trial data and represent a higher evidence bar than general wellness marketing.
MHRA (UK): The MHRA has not specifically regulated consumer PBM devices but has issued guidance on LED-based therapeutic devices under the Medical Devices Regulations 2002. Devices making specific medical claims (e.g., “treats arthritis”) are required to hold appropriate CE/UKCA marking.
Australian TGA: The Therapeutic Goods Administration in Australia has been more proactive, classifying several PBM devices as Class IIa medical devices requiring clinical evidence for listed indications.

The Trend

Expect tighter regulation as PBM moves from fringe to mainstream. This is broadly positive for consumers — it should reduce the number of underpowered, poorly designed devices on the market and increase the availability of independently tested products.

Other Notable Research (2024–2026)

PBM for Oral Mucositis

The Multinational Association of Supportive Care in Cancer (MASCC) updated its guidelines in 2024 to strongly recommend PBM for prevention of oral mucositis in patients receiving head-and-neck radiotherapy or high-dose chemotherapy. This is one of the few Grade A recommendations for PBM from a major medical body (Zadik Y et al., Supportive Care in Cancer, 2024).

Bone Healing

A 2025 meta-analysis of 14 RCTs found that PBM significantly accelerated fracture healing, with treated patients showing radiographic union an average of 2.1 weeks earlier than controls. The effect was most pronounced in long bone fractures treated with 810–850 nm at 3–5 J/cm² (Lasers in Medical Science, 2025).

Athletic Performance

Leal-Junior et al. published an updated Cochrane-style review in 2024 confirming that pre-exercise PBM (810–850 nm) delays fatigue onset and reduces post-exercise creatine kinase levels across 40+ RCTs. The evidence is now strong enough that some sporting bodies are considering whether PBM constitutes a “performance-enhancing” intervention — though no governing body has moved to restrict its use.

Thyroid Function

An intriguing 2024 Brazilian trial (Höfling DB et al.) treated patients with Hashimoto’s thyroiditis using 830 nm LLLT applied to the thyroid gland. Over 9 months, treated patients showed reduced thyroid antibody levels and some were able to reduce their levothyroxine dose. This builds on earlier work by the same group (PMID: 28862519) and suggests PBM may modulate autoimmune thyroid inflammation.

What to Watch in 2026–2027

Several large trials are expected to report results in the next 12–18 months:

Phase 3 RLRL myopia trial — the largest yet, with 800+ children across 15 centres
LIGHT-AD: a US-based Phase 3 trial of tPBM for Alzheimer’s disease
PBM for major depression: two sham-controlled trials of transcranial PBM for treatment-resistant depression are recruiting in Australia and the US
Gut microbiome RCT: the full-scale IBS trial from the University of Sydney
Diabetic wound healing: an NHS-funded trial of PBM for diabetic foot ulcers

These trials will either consolidate PBM’s move into mainstream medicine or reveal the limitations of translating cell and animal work into clinical practice. Either way, the next two years will be decisive for the field.

Summary

Red light therapy research in 2024–2026 has moved well beyond skin rejuvenation and pain relief. The myopia prevention data is robust and practice-changing. Transcranial PBM for neurodegeneration has reached the level of sham-controlled trials in high-impact journals. The gut microbiome connection, whilst early, opens an entirely new therapeutic frontier. And hardware innovation is making PBM more accessible, portable, and affordable.

The field’s biggest challenge remains the gap between laboratory promise and clinical proof at scale. But the direction of travel is clear: photobiomodulation is becoming a serious, evidence-based therapeutic modality.

Key sources: Jiang et al. (2022) PMID: 34861284 · Chao et al. (2025) JAMA Network Open · Liebert et al. (2021) PMID: 34358812 · Moskvin & Khadartsev (2024) · Zadik et al. (2024) · Saltmarche et al. (2017) PMID: 28186867 · Leal-Junior et al. (2024) · Höfling et al. (2024)